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