This worksheet guides students through simplifying radicals, expanding brackets, and squaring surd expressions.
Math worksheet for simplifying radicals with three sections of algebra problems.
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Step-by-step solution for: Simplifying Radicals (C) Worksheet | Fun and Engaging Algebra I ...
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Show Answer Key & Explanations
Step-by-step solution for: Simplifying Radicals (C) Worksheet | Fun and Engaging Algebra I ...
Let’s solve each problem step by step. We’ll go section by section, simplifying radicals and expanding expressions carefully.
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Section A: Simplify the following radicals
We combine like terms — that means only add or subtract radicals with the same number under the root (√).
1) 5√2 + 7√2 = (5+7)√2 = 12√2
2) 7√2 – 4√2 + 9√3 – 2√3
= (7–4)√2 + (9–2)√3 = 3√2 + 7√3
3) 11√5 + 3√7 + 4√5 + 6√7
= (11+4)√5 + (3+6)√7 = 15√5 + 9√7
4) 16√5 + 9√7 – 7√5 – 4√7
= (16–7)√5 + (9–4)√7 = 9√5 + 5√7
5) 3√2 + 7√3 – 7√3 – 8√2
= (3–8)√2 + (7–7)√3 = –5√2 + 0 = –5√2
Now for problems 6–10, we need to simplify the radicals first before combining.
6) √18 + √50
√18 = √(9×2) = 3√2
√50 = √(25×2) = 5√2
So: 3√2 + 5√2 = 8√2
7) √72 – √8
√72 = √(36×2) = 6√2
√8 = √(4×2) = 2√2
So: 6√2 – 2√2 = 4√2
8) 4√12 + 2√27
√12 = √(4×3) = 2√3 → 4×2√3 = 8√3
√27 = √(9×3) = 3√3 → 2×3√3 = 6√3
So: 8√3 + 6√3 = 14√3
9) 5√28 – 3√63
√28 = √(4×7) = 2√7 → 5×2√7 = 10√7
√63 = √(9×7) = 3√7 → 3×3√7 = 9√7
So: 10√7 – 9√7 = √7
10) 2√45 + 5√20 – 4√98
√45 = √(9×5) = 3√5 → 2×3√5 = 6√5
√20 = √(4×5) = 2√5 → 5×2√5 = 10√5
√98 = √(49×2) = 7√2 → 4×7√2 = 28√2
So: 6√5 + 10√5 – 28√2 = 16√5 – 28√2
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Section B: Expand the parentheses and simplify the radicals
Use distributive property (multiply outside term by each inside term), then simplify.
1) √3(2 – √3) = 2√3 – (√3 × √3) = 2√3 – 3 → –3 + 2√3
2) 2√7(7 – √7) = 2√7×7 – 2√7×√7 = 14√7 – 2×7 = 14√7 – 14 → –14 + 14√7
3) √5(5√5 – √3) = √5×5√5 – √5×√3 = 5×5 – √15 = 25 – √15 → 25 – √15
4) 2√11(4 – √11) = 2√11×4 – 2√11×√11 = 8√11 – 2×11 = 8√11 – 22 → –22 + 8√11
5) (√7 + 3)(√7 – 3) → This is difference of squares: (a+b)(a-b) = a² – b²
= (√7)² – (3)² = 7 – 9 = –2
6) (8 + √5)(8 – √5) → Again, difference of squares
= 8² – (√5)² = 64 – 5 = 59
7) (5 + √3)(4 + 2√3)
Multiply using FOIL:
First: 5×4 = 20
Outer: 5×2√3 = 10√3
Inner: √3×4 = 4√3
Last: √3×2√3 = 2×3 = 6
Add: 20 + 6 + 10√3 + 4√3 = 26 + 14√3 → 26 + 14√3
8) (7√5 + 2)(√5 + 4)
FOIL:
First: 7√5×√5 = 7×5 = 35
Outer: 7√5×4 = 28√5
Inner: 2×√5 = 2√5
Last: 2×4 = 8
Add: 35 + 8 + 28√5 + 2√5 = 43 + 30√5 → 43 + 30√5
9) (1 – 3√7)(6 – 3√7)
FOIL:
First: 1×6 = 6
Outer: 1×(-3√7) = -3√7
Inner: -3√7×6 = -18√7
Last: (-3√7)×(-3√7) = 9×7 = 63
Add: 6 + 63 + (-3√7 -18√7) = 69 – 21√7 → 69 – 21√7
10) (√3 – 1)(9√3 + 5)
FOIL:
First: √3×9√3 = 9×3 = 27
Outer: √3×5 = 5√3
Inner: -1×9√3 = -9√3
Last: -1×5 = -5
Add: 27 – 5 + 5√3 – 9√3 = 22 – 4√3 → 22 – 4√3
11) (4√7 + 3)(3√7 – 1)
FOIL:
First: 4√7×3√7 = 12×7 = 84
Outer: 4√7×(-1) = -4√7
Inner: 3×3√7 = 9√7
Last: 3×(-1) = -3
Add: 84 – 3 + (-4√7 + 9√7) = 81 + 5√7 → 81 + 5√7
12) (4√3 – √2)(3√3 – 4√2)
FOIL:
First: 4√3×3√3 = 12×3 = 36
Outer: 4√3×(-4√2) = -16√6
Inner: -√2×3√3 = -3√6
Last: -√2×(-4√2) = 4×2 = 8
Add: 36 + 8 + (-16√6 – 3√6) = 44 – 19√6 → 44 – 19√6
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Section C: Expand the parentheses and simplify the radicals
These involve squaring binomials or more complex expansions.
Recall: (a + b)² = a² + 2ab + b²
(a – b)² = a² – 2ab + b²
1) (√2 + 1)² = (√2)² + 2×√2×1 + 1² = 2 + 2√2 + 1 = 3 + 2√2
2) (√11 – 2)² = (√11)² – 2×√11×2 + 2² = 11 – 4√11 + 4 = 15 – 4√11
3) (3 – √5)² = 3² – 2×3×√5 + (√5)² = 9 – 6√5 + 5 = 14 – 6√5
4) √22(√3 + √7)²
First expand (√3 + √7)² = (√3)² + 2√3√7 + (√7)² = 3 + 2√21 + 7 = 10 + 2√21
Now multiply by √22: √22×(10 + 2√21) = 10√22 + 2√(22×21) = 10√22 + 2√462
Can’t simplify √462 further (462 = 2×3×7×11, no square factors) → 10√22 + 2√462
5) √11(√11 – √6)²
First expand (√11 – √6)² = (√11)² – 2√11√6 + (√6)² = 11 – 2√66 + 6 = 17 – 2√66
Now multiply by √11: √11×(17 – 2√66) = 17√11 – 2√(11×66)
But 11×66 = 726 → √726 = √(121×6) = 11√6
So: 17√11 – 2×11√6 = 17√11 – 22√6 → 17√11 – 22√6
6) ((√2)³ + √5)²
First, (√2)³ = (√2)² × √2 = 2√2
So expression becomes: (2√2 + √5)²
Now expand: (2√2)² + 2×2√2×√5 + (√5)² = 4×2 + 4√10 + 5 = 8 + 5 + 4√10 = 13 + 4√10
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Final Answer:
Section A
1) 12√2
2) 3√2 + 7√3
3) 15√5 + 9√7
4) 9√5 + 5√7
5) –5√2
6) 8√2
7) 4√2
8) 14√3
9) √7
10) 16√5 – 28√2
Section B
1) –3 + 2√3
2) –14 + 14√7
3) 25 – √15
4) –22 + 8√11
5) –2
6) 59
7) 26 + 14√3
8) 43 + 30√5
9) 69 – 21√7
10) 22 – 4√3
11) 81 + 5√7
12) 44 – 19√6
Section C
1) 3 + 2√2
2) 15 – 4√11
3) 14 – 6√5
4) 10√22 + 2√462
5) 17√11 – 22√6
6) 13 + 4√10
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Section A: Simplify the following radicals
We combine like terms — that means only add or subtract radicals with the same number under the root (√).
1) 5√2 + 7√2 = (5+7)√2 = 12√2
2) 7√2 – 4√2 + 9√3 – 2√3
= (7–4)√2 + (9–2)√3 = 3√2 + 7√3
3) 11√5 + 3√7 + 4√5 + 6√7
= (11+4)√5 + (3+6)√7 = 15√5 + 9√7
4) 16√5 + 9√7 – 7√5 – 4√7
= (16–7)√5 + (9–4)√7 = 9√5 + 5√7
5) 3√2 + 7√3 – 7√3 – 8√2
= (3–8)√2 + (7–7)√3 = –5√2 + 0 = –5√2
Now for problems 6–10, we need to simplify the radicals first before combining.
6) √18 + √50
√18 = √(9×2) = 3√2
√50 = √(25×2) = 5√2
So: 3√2 + 5√2 = 8√2
7) √72 – √8
√72 = √(36×2) = 6√2
√8 = √(4×2) = 2√2
So: 6√2 – 2√2 = 4√2
8) 4√12 + 2√27
√12 = √(4×3) = 2√3 → 4×2√3 = 8√3
√27 = √(9×3) = 3√3 → 2×3√3 = 6√3
So: 8√3 + 6√3 = 14√3
9) 5√28 – 3√63
√28 = √(4×7) = 2√7 → 5×2√7 = 10√7
√63 = √(9×7) = 3√7 → 3×3√7 = 9√7
So: 10√7 – 9√7 = √7
10) 2√45 + 5√20 – 4√98
√45 = √(9×5) = 3√5 → 2×3√5 = 6√5
√20 = √(4×5) = 2√5 → 5×2√5 = 10√5
√98 = √(49×2) = 7√2 → 4×7√2 = 28√2
So: 6√5 + 10√5 – 28√2 = 16√5 – 28√2
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Section B: Expand the parentheses and simplify the radicals
Use distributive property (multiply outside term by each inside term), then simplify.
1) √3(2 – √3) = 2√3 – (√3 × √3) = 2√3 – 3 → –3 + 2√3
2) 2√7(7 – √7) = 2√7×7 – 2√7×√7 = 14√7 – 2×7 = 14√7 – 14 → –14 + 14√7
3) √5(5√5 – √3) = √5×5√5 – √5×√3 = 5×5 – √15 = 25 – √15 → 25 – √15
4) 2√11(4 – √11) = 2√11×4 – 2√11×√11 = 8√11 – 2×11 = 8√11 – 22 → –22 + 8√11
5) (√7 + 3)(√7 – 3) → This is difference of squares: (a+b)(a-b) = a² – b²
= (√7)² – (3)² = 7 – 9 = –2
6) (8 + √5)(8 – √5) → Again, difference of squares
= 8² – (√5)² = 64 – 5 = 59
7) (5 + √3)(4 + 2√3)
Multiply using FOIL:
First: 5×4 = 20
Outer: 5×2√3 = 10√3
Inner: √3×4 = 4√3
Last: √3×2√3 = 2×3 = 6
Add: 20 + 6 + 10√3 + 4√3 = 26 + 14√3 → 26 + 14√3
8) (7√5 + 2)(√5 + 4)
FOIL:
First: 7√5×√5 = 7×5 = 35
Outer: 7√5×4 = 28√5
Inner: 2×√5 = 2√5
Last: 2×4 = 8
Add: 35 + 8 + 28√5 + 2√5 = 43 + 30√5 → 43 + 30√5
9) (1 – 3√7)(6 – 3√7)
FOIL:
First: 1×6 = 6
Outer: 1×(-3√7) = -3√7
Inner: -3√7×6 = -18√7
Last: (-3√7)×(-3√7) = 9×7 = 63
Add: 6 + 63 + (-3√7 -18√7) = 69 – 21√7 → 69 – 21√7
10) (√3 – 1)(9√3 + 5)
FOIL:
First: √3×9√3 = 9×3 = 27
Outer: √3×5 = 5√3
Inner: -1×9√3 = -9√3
Last: -1×5 = -5
Add: 27 – 5 + 5√3 – 9√3 = 22 – 4√3 → 22 – 4√3
11) (4√7 + 3)(3√7 – 1)
FOIL:
First: 4√7×3√7 = 12×7 = 84
Outer: 4√7×(-1) = -4√7
Inner: 3×3√7 = 9√7
Last: 3×(-1) = -3
Add: 84 – 3 + (-4√7 + 9√7) = 81 + 5√7 → 81 + 5√7
12) (4√3 – √2)(3√3 – 4√2)
FOIL:
First: 4√3×3√3 = 12×3 = 36
Outer: 4√3×(-4√2) = -16√6
Inner: -√2×3√3 = -3√6
Last: -√2×(-4√2) = 4×2 = 8
Add: 36 + 8 + (-16√6 – 3√6) = 44 – 19√6 → 44 – 19√6
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Section C: Expand the parentheses and simplify the radicals
These involve squaring binomials or more complex expansions.
Recall: (a + b)² = a² + 2ab + b²
(a – b)² = a² – 2ab + b²
1) (√2 + 1)² = (√2)² + 2×√2×1 + 1² = 2 + 2√2 + 1 = 3 + 2√2
2) (√11 – 2)² = (√11)² – 2×√11×2 + 2² = 11 – 4√11 + 4 = 15 – 4√11
3) (3 – √5)² = 3² – 2×3×√5 + (√5)² = 9 – 6√5 + 5 = 14 – 6√5
4) √22(√3 + √7)²
First expand (√3 + √7)² = (√3)² + 2√3√7 + (√7)² = 3 + 2√21 + 7 = 10 + 2√21
Now multiply by √22: √22×(10 + 2√21) = 10√22 + 2√(22×21) = 10√22 + 2√462
Can’t simplify √462 further (462 = 2×3×7×11, no square factors) → 10√22 + 2√462
5) √11(√11 – √6)²
First expand (√11 – √6)² = (√11)² – 2√11√6 + (√6)² = 11 – 2√66 + 6 = 17 – 2√66
Now multiply by √11: √11×(17 – 2√66) = 17√11 – 2√(11×66)
But 11×66 = 726 → √726 = √(121×6) = 11√6
So: 17√11 – 2×11√6 = 17√11 – 22√6 → 17√11 – 22√6
6) ((√2)³ + √5)²
First, (√2)³ = (√2)² × √2 = 2√2
So expression becomes: (2√2 + √5)²
Now expand: (2√2)² + 2×2√2×√5 + (√5)² = 4×2 + 4√10 + 5 = 8 + 5 + 4√10 = 13 + 4√10
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Final Answer:
Section A
1) 12√2
2) 3√2 + 7√3
3) 15√5 + 9√7
4) 9√5 + 5√7
5) –5√2
6) 8√2
7) 4√2
8) 14√3
9) √7
10) 16√5 – 28√2
Section B
1) –3 + 2√3
2) –14 + 14√7
3) 25 – √15
4) –22 + 8√11
5) –2
6) 59
7) 26 + 14√3
8) 43 + 30√5
9) 69 – 21√7
10) 22 – 4√3
11) 81 + 5√7
12) 44 – 19√6
Section C
1) 3 + 2√2
2) 15 – 4√11
3) 14 – 6√5
4) 10√22 + 2√462
5) 17√11 – 22√6
6) 13 + 4√10
Parent Tip: Review the logic above to help your child master the concept of simplifying radical expressions worksheet with answers.