how do you substitute x+6y=2 and 5x+4y=36

Question

I really need help on this please.!!!!!

Answer 1

line 1...x+6y=1   or x=-6y+1

line 2...5x+4y=36

line 2...5*(-6y+1)+4y=36

-30y+5+4y=36...-26y=36-5...-26y=31...y=-(31/26)...y=-1.192307692

x=-6y+1...=1+6*(1.192307692)=1+7.153846154

x=8.153846154

Comments

Shouldn't line 1 be x=2-6y? Whoops!

Answer 2

From equation 1 x=2-6y. Where x appears in equation 2 we replace it with this value of x. This changes equation 2 to 5(2-6y)+4y=36. Open the brackets: 10-30y+4y=36, so 10-26y=36, and 10-36=26y. So 26y=-26 and y=-1. We can now substitute this value of y in x=2-6y, so x=2+6=8. Check out these values for x and y in the original equations: 8-6=2 and 40-4=36. Correct!