Question

Which line shows the first error in the solution? 5(x-5)=15 (1)       5x-25=15 (2)      5x-25=15-25 (3)  5x= -10 (4)  5x/5 = -10/5 (5) x=-2 (6) Answers: A. line 2 B line 3 C. line 4 D. line 5 

Answer 1

$5(x-5)=15\\5x-25=15\ \ (ok)\\5x-25=15-25\ \ \ the\ first\ error\ in\ the\ solution\\ \\Ans.\ B\ line\ 3$

Answer 2

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.