Answer:
(3x -2)(5x +2)
Step-by-step explanation:
To factor a quadratic ax²+bx+c, you look for factors of ac that total b. Here, that means you're looking for factors of (15)(-4) = -60 that total -4. We can look at factor pairs of -60 to see what the choices might be:
-60 = -60·1 = -30·2 = -20·3 = -15·4 = -12·5 = -10·6
The sums of these pairs are -59, -28, -17, -11, -7, and -4. So, the numbers we're looking for are -10 and 6. We can rewrite the expression using these numbers to divide -4x into parts that have the sum of -4x:
= 15x² -10x +6x -4
Grouping terms in pairs and factoring the pairs gives ...
= 5x(3x -2) +2(3x -2)
Using the distributive property again, we get ...
= (5x +2)(3x -2) . . . . . . . . factorization of the given quadratic
Answer:
[tex] \sf \longmapsto \: 15 {x}^{2} - 4x - 4[/tex]
[tex] \sf \longmapsto \:(15 {x}^{2} + 6x) + ( - 10x - 4)[/tex]
[tex] \sf \longmapsto \:3x(5x + 2) - 2(5x + 2)[/tex]
[tex] \sf \longmapsto \:(3x - 2)(5x + 2)[/tex]
