Question

Solve 2x + 3y = 4 and -x + 4y = -13 algebraically

Answer 1

2x + 3y = 4

-x + 4y = -13 /×2

2x + 3y = 4

-2x + 8y = -26

11y = -22

y = -2

2x + 3(-2) = 4

2x + (-6) = 4

2x = 10

x = 5

check:

2(5) + 3(-2) = 4

10 + (-6) = 4

4 = 4

L = R

-(5) + 4(-2) = -13

-5 + (-8) = -13

-13 = -13

L = R

∴ x = 5, y = -2