157k views
3 votes
What common error(s) did this student make? What is the correct solution for x? Please help

What common error(s) did this student make? What is the correct solution for x? Please-example-1
User Ccamara
by
4.5k points

2 Answers

7 votes

Answer:

x = 3

Explanation:

The first error was in the 2nd line: -5(x - 1) is -5x + 5, not -5x - 5 = 20.

Continuing the solution:

10x - 5x + 5 = 20

Combining like terms, we get

5x = 15, and so x = 3

User Kowan
by
5.4k points
4 votes

Answer:

10x - 5(x - 1) = 20

10x - 5x + 5 = 20

5x + 5 = 20

5x = 20 - 5

5x = 15

x = 15/5

x = 3

Explanation:

User JHowIX
by
5.2k points