Question

Factor 4x^2 + 12x + 5 4x - 5" alt="12x^{2} - 4x - 5" align="absmiddle" class="latex-formula">
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Answer 1

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).