Simple,
either FOIL or use the box, making the equation look like this,
(4x-2)(12x+42)=
=48x^2+144x-84.
Then, factor out a 12.
Your answer factored out and simplified,
12(2x-1)(2x+7)
a=48,b=144,c=-84.
Answer:
Divide the numerator and denominator of the given rate by the denominator of the given rate.
Step-by-step explanation: