solving system of equations by substitution

Question

x-2y=-1

3y=x+4

Answer 1

x-2y =-1   eq1

3y-4 = x    eq2   (rewritten)

 

Substitute eq2 into eq1.  We have

 

 x-2y =-1

3y-4-2y = -1

y-4 = -1

y = 3

 

Substitute this value of y into eq2.

 

3y = x+4

3(3) = x+4

9= x+4

5= x

 

Your solutions are

 

x = 5

y = 3