solve the following system of equations using the substitution method

Question

-3y+x=7

5x+6y=14

Answer 1

(i)  -3y + x = 7
(ii)  5x + 6y = 14

 

From (i) get

 

x = 7 + 3y

 

and substitute into (ii) to find y.

 

5(7 + 3y) + 6y = 14

35 + 15y + 6y = 14

21y = -21

y = -1

 

Now substitute y = -1 into either equation to get x.  If you use (i) you get

 

x = 7 + 3(-1) = 7 - 3 = 4

x = 4

 

Go ahead and test the solution.