Answer
$$x=20$$ $$y=8$$
Work Step by Step
Equation 1: $x + y = 28$
Equation 2: $x - y = 12$
Add equation 1 and 2:
$$x + y = 28$$ $$+$$ $$x - y = 12$$ $$=$$ $$2x=40$$
Divide both sides by $2$:
$$\frac{2x}{2}=\frac{40}{2}$$ $$x=20$$
Substitute this value of $x$ to equation 1:
$$x + y = 28$$ $$20 + y = 28$$
Subtract $20$ from both sides:
$$20 -20+ y = 28-20$$ $$y=8$$
Use equation 2 to check:
$$x - y = 12$$ $$20 - 8 = 12$$ $$12=12$$
