Answer:
Step-by-step explanation:
2x(x - 3) + 7(x - 3)
2x^2 - 6x + 7x - 21
reduce
2x^2 + x - 21
if this is equal to 0 then:
2x^2 + x - 21 = 0
factored:
(2x + 7)(x - 3) = 0
How that was done:
Divide the (2x^2) into (2x) and (x).
Divide the (-21) into (+7) and (-3). You choose these numbers so that their sum, when multiplied by (2x) and (-3), adds up to (+x).
