Solve the nonlinear equation by substituting

Question

 x + 2y = 1
5x – 4y = -23

Answer 1

x + 2y = 1 ⇒ x = -2y + 1
5x – 4y = -23

 

5(-2y + 1) - 4y = -23

 

Can you solve for y and answer? (If you are in Trig you should!)

 

Answer 2

Actually, this is a system of LINEAR equations.  From the top equation, get

 

x = 1 - 2y

 

Then substitute 1-2y for x in the bottom equation and solve for y.  Finally, substitute the result for y into either equation and solve for x.  You should get 

 

x = -3

y = 2