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In Mathematics / Middle School | 2014-05-16

Which line shows the first error in the solution?

1. \(5(x-5) = 15\)
2. \(5x - 25 = 15\)
3. \(5x - 25 = 15 - 25\)
4. \(5x = -10\)
5. \(\frac{5x}{5} = \frac{-10}{5}\)
6. \(x = -2\)

Answers:
A. line 2
B. line 3
C. line 4
D. line 5

Asked by mjchey

Answer (3)

5 ( x − 5 ) = 15 5 x − 25 = 15 ( o k ) 5 x − 25 = 15 − 25 t h e f i rs t error in t h e so l u t i o n A n s . B l in e 3

Answered by kate200468 | 2024-06-10

Answer : B. line 3
5(x-5)=15 ----> 1
We remove the parenthesis by distributing 5 inside the parenthesis.
5x - 25 = 15 ----> 2
To get rid of -25, add 25 on both sides
5x - 25 + 25 = 15 + 25 ----> 3
5x = 40 ----> 4
Divide by 5 on both sides
x = 8
From the given options we can see that there is a error in line 3.
Instead of adding 25 , they subtracted 25
So line 3 shows the first error.

Answered by lisboa | 2024-06-11

The first error occurs in line 3, where the process incorrectly subtracts 25 instead of adding it to both sides of the equation. Therefore, the correct answer is B. line 3.
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Answered by lisboa | 2024-12-20