Ilana tried to determine the solution for a system of equations. Her work is shown below.

y = 3/2x + 20

y = 1/2x + 15

Step 1: 1/2x + 15 = 3/2x + 20
Step 2: 1/2x = 3/2x + 5
Step 3: x = 5
Step 4: 3/2(5) + 15 = 15/2 + 15 = 22.5

Question

Ilana tried to determine the solution for a system of equations. Her work is shown below.

y = 3/2x + 20

y = 1/2x + 15

Step 1: 1/2x + 15 = 3/2x + 20
Step 2: 1/2x = 3/2x + 5
Step 3:  x = 5
Step 4: 3/2(5) + 15 = 15/2 + 15 = 22.5

anonymous · Answer

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

anonymous · Answer

Step 3: x=-5