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?
Step 1
Step 2
Step 3
Step 4

Answer 1

-2*10 = -20 not -10

Answer 2

step 2

Answer 3

thanks

Answer 4

good @Mehek14 @automaticloveletter