Let's solve each equation step by step. I'll go through all the problems on your worksheet, explaining each solution clearly.
---
1) $ 2a - 8a = 12 - 8a $
Step 1: Combine like terms on the left side:
$$
(2a - 8a) = -6a
$$
So the equation becomes:
$$
-6a = 12 - 8a
$$
Step 2: Add $ 8a $ to both sides to get all variables on one side:
$$
-6a + 8a = 12
\Rightarrow 2a = 12
$$
Step 3: Divide both sides by 2:
$$
a = \frac{12}{2} = 6
$$
✔ Answer: $ a = 6 $
*(You already got this correct!)*
---
2) $ r - 6 = 6 + 4r $
Step 1: Move all variable terms to one side and constants to the other.
Subtract $ 4r $ from both sides:
$$
r - 4r - 6 = 6
\Rightarrow -3r - 6 = 6
$$
Step 2: Add 6 to both sides:
$$
-3r = 6 + 6 = 12
$$
Step 3: Divide by -3:
$$
r = \frac{12}{-3} = -4
$$
✘ You wrote $ r = -3 $, but that’s incorrect.
✔ Correct Answer: $ r = -4 $
---
3) $ 1 + 4x = -5 + 7x $
Step 1: Subtract $ 7x $ from both sides:
$$
1 + 4x - 7x = -5
\Rightarrow 1 - 3x = -5
$$
Step 2: Subtract 1 from both sides:
$$
-3x = -5 - 1 = -6
$$
Step 3: Divide by -3:
$$
x = \frac{-6}{-3} = 2
$$
✔ Answer: $ x = 2 $
---
4) $ 5r - 2 = 6r + 5 $
Step 1: Subtract $ 6r $ from both sides:
$$
5r - 6r - 2 = 5
\Rightarrow -r - 2 = 5
$$
Step 2: Add 2 to both sides:
$$
-r = 5 + 2 = 7
$$
Step 3: Multiply both sides by -1:
$$
r = -7
$$
✔ Answer: $ r = -7 $
---
5) $ 5x + 7 = -14 + 8x $
Step 1: Subtract $ 8x $ from both sides:
$$
5x - 8x + 7 = -14
\Rightarrow -3x + 7 = -14
$$
Step 2: Subtract 7 from both sides:
$$
-3x = -14 - 7 = -21
$$
Step 3: Divide by -3:
$$
x = \frac{-21}{-3} = 7
$$
✔ Answer: $ x = 7 $
---
6) $ -2 + 5n = 4n + 2 $
Step 1: Subtract $ 4n $ from both sides:
$$
-2 + 5n - 4n = 2
\Rightarrow -2 + n = 2
$$
Step 2: Add 2 to both sides:
$$
n = 2 + 2 = 4
$$
✔ Answer: $ n = 4 $
---
7) $ 4p - 3 = -9 + 7p $
Step 1: Subtract $ 7p $ from both sides:
$$
4p - 7p - 3 = -9
\Rightarrow -3p - 3 = -9
$$
Step 2: Add 3 to both sides:
$$
-3p = -9 + 3 = -6
$$
Step 3: Divide by -3:
$$
p = \frac{-6}{-3} = 2
$$
✔ Answer: $ p = 2 $
---
8) $ -4 - 5k = -5k - 4 $
Step 1: Add $ 5k $ to both sides:
$$
-4 - 5k + 5k = -4
\Rightarrow -4 = -4
$$
This is always true — it’s an identity.
✔ Answer: Infinite solutions (all real numbers)
Because both sides are identical after simplification.
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✔ Final Answers:
| Problem | Answer |
|--------|--------|
| 1) | $ a = 6 $ |
| 2) | $ r = -4 $
✘ (you had -3) |
| 3) | $ x = 2 $ |
| 4) | $ r = -7 $ |
| 5) | $ x = 7 $ |
| 6) | $ n = 4 $ |
| 7) | $ p = 2 $ |
| 8) |
Infinite solutions |
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Parent Tip: Review the logic above to help your child master the concept of solving equations with variables on both sides worksheet answers 2 4.