Solve for y: (see below)

Question

3x+(-4)=2y+9

Why can't we subsitute x with 0 to solve for y? is it because the equation isn't linear?

Answer 1

If you set x to zero, you only get the y intercept. The equation is linear, so the value of y depends on the value of x. Remember y=mx+b., has to show all values of x and y unless otherwise stated.so, 3x+(-4)=2y+9 should go stepwise 3x-4=2y+9, then 3x-13=2y then (3x-13)/2 =y or 3/2x-13/2=y.

Answer 2

Yes you can solve for y by substituting 0 for x. Yet that determines only one of an unlimited number of solutions.

To solve for y:

3x + (-4) = 2y + 9

3x - 4 = 2y + 9

3x - 13 = 2y

(3x - 13) / 2 = y

This equation states the relation between all x and y.

Also it is linear.