Question

Mira was solving for y in the following problem l. However, she did something wrong. Describe and correct the error in the work shown.2x-y=5y=-2x+5

Answer 1

The initial equation is:

`2x-y=5`

Then, in order to isolate y, we need to subtract 2x from each side of the equation:

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

Then, we multiply both sides by -1:

`y=2x-5`

The equation Mira wrote is y=-2x+5​. So we can see that her error was not changing the signs of the terms in the right side of the equation.

In order to correct her error, we just need to change the signs in the right side of the equation:

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