Question

Use this system of equations to answer the questions

that follow.
4x - 9y = 7
-2x + 3y = 4

Answer 1

the first one is 2 the second one is 3

Explanation:

Answer 2

1. To eliminate x-term, multiply the second by -2

2. To eliminate y-term, multiply the second by 3

Explanation:

4x - 9y = 7 (1)

-2x + 3y = 4 (2)

1. To eliminate x-term, multiply the second by -2

-2x + 3y = 4 (2) × 2

-4x + 6y = 8 (3)

4x - 9y = 7 (1)

Add (3) and (1)

6y - 9y = 8 + 7

-3y = 15

y = 15/-3

y = -5

4x - 9y = 7 (1)

4x - 9(-5) = 7

4x + 45 = 7

4x = 7 - 45

4x = -38

x = -38/4

x = -9.5

4x - 9y = 7 (1)

-2x + 3y = 4 (2)

2. To eliminate y-term, multiply the second by 3

-2x + 3y = 4 (2) × 3

-6x + 9y = 12 (3)

4x - 9y = 7 (1)

-6x + 4x = 12 + 7

-2x = 19

x = 19/-2

x = -9.5

4x - 9y = 7 (1)

4(-9.5) - 9y = 7

-38 - 9y = 7

-38 - 7 = 9y

-45 = 9y

y = -45/9

y = -5