Question

In which step did the student first make an error?Step 1Step 2Step 3Step 4

Answer 1

Notice that on step two, where equation 1 is simplifed, we have the following when we multiply by -2 the first equation:

`\begin{gathered} -2\cdot(y=15-2z) \\ \Rightarrow-2y=-2(15)-2(-2z) \\ \Rightarrow-2y=-30+4z \end{gathered}`

therefore, the error is on the step 2