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