Question

Given the system of equations: 5x + 2y = 3 4x − 8y = 12 solve for (x, y) using elimination. a. (−7, 5) b. (−5, −4) c. (1, −1) d. (3, −6)

Answer 1

c. (1,-1)

Explanation:

5x + 2y = 3 4x – 8y = 12 Solve for (x, y)

4x-8y=12

+8y +8y

4x=12+8y

Divide both sides by 4

4x/4=(12+8y)/4

x=3+2y

Then take x equation and input into 5x + 2y = 3

5(3+2y)+2y=3

15+10y+2y=3

Add 10y and 2y

15+12y=3

Subtract 15 on both sides

15-15+12y=3-15

12y=-12

Divide 12 both sides

12y÷12=-12÷12

Y = -1

Insert the Y equation into 4x – 8y = 12

4x-8(-1)=12

4x+8=12

Subtract 8 on both sides

4x-8-8=12-8

4x=4

Divide 4 both sides

4x÷4=4÷4

X = 1

Answer: C. (1, -1)