12=4x-3y Begin by moving the 4x away from the y. -3y=-4x+12. To get y by itself, divide both sides by -3. y= 4/3x -4. Therefore the slope is 4/3.
(f+g)(x)=0
f (x) + g (x)=0
now,
substitute their values
x^2 -4x + x -18 = 0
x^2 -3x -18 =0
x^2 - 6x + 3x - 18 =0
x (x-6) + 3 (x-6) = 0
(x-6)(x+3) = 0
we have to find it's zeroes (or roots) now:
x-6 =0
x = 6
x +3 =0
x = -3
-2 + 5 is the same as 5 - 2
5-2= 3
9x+8y=15
9x+8y=30
There can't be a solution because 9x+8y equal different things in both.
Hope this helps :)