Answer:
(2x + 5)(2x + 1).
(6x - 5)(2x + 1).
Step-by-step explanation:
4x^2 + 12x + 5.
Use the 'ac' method:
a * c = 4 * 5 = 20 so we need 2 numbers whose product is 20 and whose sum is +12.:- 2 and 10 look good, so we write:
4x^2 + 2x + 10x + 5
Now we factor by grouping:-
= 2x(2x + 1) + 5(2x + 1)
= (2x + 5)(2x + 1) (answer).
12x^2 - 4x - 5
ac = 12*-5 = - 60 and we need 2 numbers sum to -4 . these numbers could be -10 and + 6:
12x^2 + 6x - 10x - 5
= 6x(2x + 1) - 5(2x + 1)
= (6x - 5)(2x + 1) (answer).