Question
Using the standard formulae, expand:
$(x-5)(2 x-1)(2 x+3)$
$(x-5)(2 x-1)(2 x+3)$
✓
Answer
$4 x^3-16 x^2-23 x+15$
[Hint.
$\begin{aligned}(x-5)(2 x-1)(2 x+3) & =(x-5)\left[4 x^2+6 x-2 x-3\right] \\ & =(x-5)\left(4 x^2+4 x-3\right) \\ & =x\left(4 x^2+4 x-3\right)-5\left(4 x^2+4 x-3\right) \text { etc.] }\end{aligned}$
[Hint.
$\begin{aligned}(x-5)(2 x-1)(2 x+3) & =(x-5)\left[4 x^2+6 x-2 x-3\right] \\ & =(x-5)\left(4 x^2+4 x-3\right) \\ & =x\left(4 x^2+4 x-3\right)-5\left(4 x^2+4 x-3\right) \text { etc.] }\end{aligned}$
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