(1B) The product $(a+b)(c+d)$
Practice
Expand and simplify.
*Write your answers with powers of $x$ in descending order. $\left(\square x^2 \pm \square x \pm \square\right)$
$\left(x+8\right)\left(x+7\right)$
$\left(x-1\right)\left(x+7\right)$
$\left(x-7\right)\left(2-x\right)$
$\left(x+1\right)\left(-1+x\right)$
$\left(-4+x\right)\left(x+3\right)$
$\left(5-x\right)\left(x+6\right)$
$\left(1+x\right)\left(9+x\right)$
$\left(-4+x\right)\left(2-x\right)$
$\left(3x-7\right)\left(x-9\right)$
$\left(4x-7\right)\left(x-5\right)$
$\left(-8x+3\right)\left(8+x\right)$
$\left(x-3\right)\left(-1+x\right)$
$\left(-4+x\right)\left(x-2\right)$
$\left(-6+5x\right)\left(7x+2\right)$
$\left(8-3x\right)\left(-1+8x\right)$
$\left(4-x\right)\left(4-5x\right)$