substitution if 2x-3y=-24 x+6y=18
i need to know how to solve the
substuitution anxd the answer.
Solve one of the equations for x. Let's use the second one.
x + 6y = 18
x = -6y + 18
Because the right side of that equation equals x, we can
substitute it in place of x in the first equation. We will then
have an equation with only one unknown, and we can solve
that for an exact value.
2x - 3y = -24
2(-6y + 18) - 3y = -24
-12y + 36 - 3y = -24
-15y + 36 = -24
-15y = -24 - 36
-15y = -60
y = -60 / -15
y = 4 <<<<<<<<<<<<<
With that, we can return to the second equation,
and solve for x.
x + 6y = 18
x + 6(4) = 18
x + 24 = 18
x = 18 - 24
x = -6 <<<<<<<<<<<<<
Plug both values into either of the original
equations to check whether or not they are correct.
2x - 3y = -24
2(-6) - 3(4) = -24
-12 - 12 = -24
-24 = -24