Ernesto tried to determine the solution for the system of equations using substitution. His work is shown below.

x _ y = 7

3x _ 2y = 8

Step 1: x = y + 7

Step 2: 3 (y + 7) _ 2y = 8

Step 3: 3y + 7 _ 2y = 8

Step 4: y + 7 = 8

Step 5: y = 1

In which step did Ernesto make the first error?

Step 1

Step 2

Step 3

Step 4

Question

Anthony Leblanc

Mathematics

12 July, 16:52

Ernesto tried to determine the solution for the system of equations using substitution. His work is shown below.

x _ y = 7

3x _ 2y = 8

Step 1: x = y + 7

Step 2: 3 (y + 7) _ 2y = 8

Step 3: 3y + 7 _ 2y = 8

Step 4: y + 7 = 8

Step 5: y = 1

In which step did Ernesto make the first error?

Step 1

Step 2

Step 3

Step 4

+3

Answers (1)

Know the Answer?

Layla Romero · Answer 1

The answer is Step 3: 3y + 7 _ 2y = 8.

Ernesto made a mistake in the step 3 because he did not multiply 3 and 7.

The correct order of steps is:

Step 1: x = y + 7

Step 2: 3 (y + 7) - 2y = 8

Step 3: 3y + 3·7 - 2y = 8

Step 4: y + 21 = 8

Step 5: y = - 13

Ernesto tried to determine the solution for the system of equations using substitution. His work is shown below.x _ y = 73x _ 2y = 8Step 1: x = y + 7Step 2: 3 (y + 7) _ 2y = 8Step 3: 3y + 7 _ 2y = 8Step 4: y + 7 = 8Step 5: y = 1In which step did Ernesto make the first error?Step 1Step 2Step 3Step 4