(1B) The product $(a+b)(c+d)$
Practice
Expand and simplify.
*Write your answers with powers of $x$ in descending order. $\left(\square x^2 \pm \square x \pm \square\right)$
$\left(x-8\right)\left(x+1\right)$
$\left(x+6\right)\left(x+7\right)$
$\left(x-1\right)\left(9-x\right)$
$\left(x-9\right)\left(8-x\right)$
$\left(2+x\right)\left(x+8\right)$
$\left(2-x\right)\left(-x+3\right)$
$\left(-2+x\right)\left(2-x\right)$
$\left(7-x\right)\left(4-x\right)$
$\left(7x-3\right)\left(3x-2\right)$
$\left(-x+8\right)\left(4x-1\right)$
$\left(x+2\right)\left(9-4x\right)$
$\left(-7x+3\right)\left(2+3x\right)$
$\left(-8+x\right)\left(-7x+1\right)$
$\left(3+4x\right)\left(2x-7\right)$
$\left(-4+3x\right)\left(1-2x\right)$
$\left(9-x\right)\left(1+6x\right)$