+23695 B = 3x+8 we want 3 times this 3 (3x+8) = 9x + 24 equal to A = 5x-4
9x+24 = 5x -4
4x = -28
x = -7
+21013 For machne A: with an input of x its output will be 5x - 4
For machine B: with an input of x its output will be 3x + 8
If machine A's output is three times machine B's output: 5x - 4 = 3(3x + 8)
5x - 4 = 9x + 24
subtract 5x from both sides: -4 = 4x + 24
subtract 24 from both sides: -28 = 4x
divide both sides by 4: -7 = x
Checking: machine A: 5x - 4 = 5(-7) - 4 = -35 - 4 = -39
machine B: 3x + 8 = 3(-7) + 8 = -21 + 8 = -13
And: -39 is three times -13.
