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

Answer 1

isolate x on one side and put all other terms on other side..here x=12-3y

Answer 2

Change the subject so that x and only x is left on the left side. The right side would be the expression you need.

Answer 3

Oh, @abhi7 beat me ;)

Answer 4

put 12-3y on eqn first

Answer 5

So, for the first equation for x I would put in 12-3y?

Answer 6

Correct.

Answer 7

Ok, thanks guys.(: