Question

The work of a student to solve a set of equations is shown below:
Equation 1: x + 2y = 10
Equation 2: 2x + 5y = 15
Step 1: −2(x + 2y) = −2(10)
2x + 5y = 15
Step 2: −2x − 4y = −10
2x + 5y = 15
Step 3: 1y = 5
Step 4: x + 2(1) = 10
Step 5: x = 8
In which step did the student first make an error?
A. Step 1
B. Step 2
C. Step 3
D. Step 4

Answer 1

hey

Answer 2

\[2(-2y+10)+ 5y = 15\]
I did this to isolate the X so that i would have something to plug into the equation does this make sense?

Answer 3

yeah

Answer 4

You can now figure out what step it is!

Answer 5

i think its step 2