4x - 9 = 7x + 12
Subtract 4x from both sides: -9 = 3x + 12
Subtract 12 from both sides: -21 = 3x
Divide both sides by 3: x = -7
7x = 3x - 12 4x=-12 x=-3
8x+30=4x+18 -4x -4x 4x+30=18 -30 -30 4x=-12 4x/4=-12/4 x=-3
-4x + 8 = -4 -4x + 8 - 8 = -4 -8 -4x = -12 -4x/-4 = -12/-4 x = 3
-12 (?)
2y = 4x + 4y = 2x + 2
-2x = -4x + 24 -2x + 4x = 24 2x = 24 x = 24/2 x = 12
If: 4x+(-12) = 8 then 4x = 20 and x = 5
It is: y = -4x+12
many solutions
-5x + x + 9 = -4x + 12 -4x + 9 = -4x + 12 9 = 12 This equation has no solution.
x= -.5
You can't solve it. But you can simplify it to get: 4x+y=2