Question

Trevor solved the system of equations below. What mistake did he make in his work?2x + y = 5x − 2y = 10y = 5 − 2xx − 2(5 − 2x) = 10x − 10 + 4x = 105x − 10 = 105x = 0x = 02(0) + y = 5y = 5 (5 points) a. He should have substituted 5 + 2x b. He combined like terms incorrectly, it should have been 4x instead of 5x c. He subtracted 10 from the right side instead of adding 10 to the right side d. He made no mistake

Answer 1

Given:

Trevor solved the system of equations below.

`\begin{gathered} 2x+y=5 \\ x-2y=10 \end{gathered}`

Trevor made the following steps to solve the system of equations:

y = 5 − 2x ⇒ correct

x − 2(5 − 2x) = 10 ⇒ correct

x − 10 + 4x = 10 ⇒ correct

5x − 10 = 10 ⇒ Wrong

5x = 0

x = 0

So, the fourth step is wrong, because he subtracted 10 from both sides

And the correct should be adding 10 to both sides

so, the answer will be option C.

c. He subtracted 10 from the right side instead of adding 10 to the right side