Question 294112
As several tutors have said, you cannot solve the equation. You can find solutions for the equation and you can graph it.
It sounds like someone told you how to graph it.
y=-3/4 x + 5
I will assume that you mean
y=-(3/4)*x + 5
so we let x=0 and we get y=5
plot (0,5)
now let y=0 and find x
0=-(3/4)x+5
-5=-3/4*x
multiply by -4/3
-5*(-4/3)=x
20/3=x
(20/3,0) 
plot this 
20/3 is almost 7 it is 6 2/3 or 6.67
We will use the slope -3/4 to find the next integer point
From (0,5) we go down 3 for y and over 4 for x
(4,2) is easier to plot that (20/3, 0)