Question

When using the substitution method, what expression for x in the second equation would be substituted in the first equation?

4x - 7y = -9
x + 3y = 12

-3y + 12
3y - 12
-3y - 12
3y + 12

Answer 1

From equation 2:

x=12-3y (equation3)

now substitue (equation 3) to the first equation.

4(12-3y)-7y=-9

then carry on solving:)
Hope this helps!

Answer 2

yes thank you very much.