How do solve the following linear system?: y = 8 x - 3 , x-3y=-1 y=8x3,x3y=1?

1 Answer
Dec 14, 2015

x=10/23 and y=11/23x=1023andy=1123

Explanation:

Substitute the first equation into the second - that is, in the second equation, wherever you see a yy you replace it with 8x-38x3.
Then the second equation becomes :
x-3(8x-3)=-1x3(8x3)=1.

This is now 1 equation in 1 unknown and we may solve for xx to obtain
x-24x+9=-1x24x+9=1
therefore x=-10/-23=10/23.

Now substitute this value back into equation 1 to find y :

therefore y=8(10/23)-3
=11/23