Answer
$2(2x+1)(x-5)$
Work Step by Step
Factoring by grouping:
1. Multiply the leading coefficient, a, and the constant, c.
2. Find the factors of ac whose sum is b.
3. Rewrite the middle term, bx, as a sum or difference using the factors from step 2.
4. Factor by grouping
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$4x^{2}-18x-10 =...$
Always start by searching for a GCF ... ($GCF=2$).
$=2(2x^{2}-9x-5)=...$
Now, the parentheses:
1. $\quad ac=-10 \qquad $
2. $\quad$sum = $-9\quad$... factors: $-10$ and $+1$
3. $\quad$ $2x^{2}-9x-5 = (2x^{2}-10\mathrm{x})+(x-5)$
4. $\quad$... $= 2x(x-5)+(1)(x-1) = (2x+1)(x-5) $
$...=2(2x^{2}+13x+15) = 2(2x+1)(x-5)$
