(4x - 2) x (12x +42) (I distributed the 6 over the 2x and the 7)
Using the FOIL method First terms (in each parenthesis) 4x times 12 x = 48x² Outer terms 4x times 42 = 168x Inner terms -2 times 12 x = -24x Last terms -2 times 42 = -84
So we have 48x² + 168x + 168x - 24x -84 Finally combine like terms:
48x² + 144x - 84 There's your quadratic expression