Question

Systems of linear equations and inequalities

solve the system of equations.
x-y=4
2x+y=5

Answer 1

∴ x = 1, y = -3

Explanation:

x - y = 4 ------ equation (1)

2x + y = 5 ------ equation (2)

Add equations (1) and (2):
(2x + y) + (x - y) = 5 - 4

2x + y - x - y = 1

∴ x = 1

Substitute x = 1 into equation (1):

1 - y = 4

-y = 3

∴ y = -3