Let’s solve each problem step by step. We’ll substitute the given values into the expressions and calculate carefully.
---
Section A: Substitute a = ?
1.
Expression: 8a – 9, a = 2
→ First: 8 × 2 = 16
→ Second: 16 – 9 = 7
→ Answer:
7
2.
Expression: 4 + 2a, a = 6
→ First: 2 × 6 = 12
→ Second: 4 + 12 = 16
→ Answer:
16
3.
Expression: a/5 + 20, a = 10
→ First: 10 ÷ 5 = 2
→ Second: 2 + 20 = 22
→ Answer:
22
4.
Expression: 11 – a/3, a = 12
→ First: 12 ÷ 3 = 4
→ Second: 11 – 4 = 7
→ Answer:
7
5.
Expression: 8a/10, a = 5
→ First: 8 × 5 = 40
→ Second: 40 ÷ 10 = 4
→ Answer:
4
---
Section B: Substitute b = ? or a and b = ?
*First part (only b):*
6.
Expression: (14b + 13)/9, b = 1
→ First: 14 × 1 = 14
→ Second: 14 + 13 = 27
→ Third: 27 ÷ 9 = 3
→ Answer:
3
7.
Expression: (52 – 2b)/7, b = 12
→ First: 2 × 12 = 24
→ Second: 52 – 24 = 28
→ Third: 28 ÷ 7 = 4
→ Answer:
4
8.
Expression: 10b – b², b = 2
→ First: b² = 2 × 2 = 4
→ Second: 10 × 2 = 20
→ Third: 20 – 4 = 16
→ Answer:
16
*Second part (a and b):*
9.
Expression: 7a + ab, a=2, b=3
→ First: 7 × 2 = 14
→ Second: a × b = 2 × 3 = 6
→ Third: 14 + 6 = 20
→ Answer:
20
10.
Expression: 9b – 6a, a=5, b=8
→ First: 9 × 8 = 72
→ Second: 6 × 5 = 30
→ Third: 72 – 30 = 42
→ Answer:
42
11.
Expression: a² + b², a=11, b=4
→ First: a² = 11 × 11 = 121
→ Second: b² = 4 × 4 = 16
→ Third: 121 + 16 = 137
→ Answer:
137
12.
Expression: 1 + 5a/b, a=12, b=6
→ First: 5 × 12 = 60
→ Second: 60 ÷ 6 = 10
→ Third: 1 + 10 = 11
→ Answer:
11
13.
Expression: (84 – 6a)/b, a=10, b=3
→ First: 6 × 10 = 60
→ Second: 84 – 60 = 24
→ Third: 24 ÷ 3 = 8
→ Answer:
8
14.
Expression: (a + b)² + 3, a=2, b=5
→ First: a + b = 2 + 5 = 7
→ Second: 7² = 49
→ Third: 49 + 3 = 52
→ Answer:
52
---
Section C: Substitute x and y
15.
Expression: (33 – 3x)/(2y), x=7, y=3
→ Numerator: 3 × 7 = 21 → 33 – 21 = 12
→ Denominator: 2 × 3 = 6
→ Final: 12 ÷ 6 = 2
→ Answer:
2
16.
Expression: xy – y², x=10, y=6
→ First: x × y = 10 × 6 = 60
→ Second: y² = 6 × 6 = 36
→ Third: 60 – 36 = 24
→ Answer:
24
17.
Expression: (xy – 3y)², x=4, y=8
→ First: x × y = 4 × 8 = 32
→ Second: 3 × y = 3 × 8 = 24
→ Third: 32 – 24 = 8 → then square it: 8² = 64
→ Answer:
64
---
Final Answer:
Section A Answers:
7, 16, 22, 7, 4
Section B Answers (first part):
3, 4, 16
Section B Answers (second part):
20, 42, 137, 11, 8, 52
Section C Answers:
2, 24, 64
Parent Tip: Review the logic above to help your child master the concept of basic substitution worksheet.
