So, since we know what is y= to. we are going to plug in that equation for y I n the 2nd equation.
for example:
y=3/4x+5
4x-3(3/4x+5)= -1
4x-9/4x+15=-1
16/4x-9/4x=-16
5/4x=-16
multiply by the reciprocal on both sides toget x.
4/5(5/4x)= (-16)4/5
x= -64/5 = -12 and 4/5ths