Use addition or substitution to find the value of x for this set of equations. 4x + 13y = 40 4x + 3y = -40

Answer 1

subtracts them...

10y=80

Y=8

Substitutes

The result I'd 4x = -64

X=-16

Solution (-16,8)

Answer 2

4x +13y=40

4x+3y= -40. Subtract equation 2 from equation 1

10 y = 80 so y=8

substitute 8 for y in equation 2

4x +3(8)=-40

4x+24=-40

4x= -64

x=-16

so solution is x=-16 y=8