0. Fundamental Concepts of Algebra

Evaluate the algebraic expression when $x=4$ and $y=-5$.

$2y-x\left(3+y\right)$

Evaluate the algebraic expression when $x=-3$ and $y=2$.

$x\left(20-15y\right)-\left|2x+y\right|$

Simplify

$-3\left(5-x\right)+10-7x$

Simplify

$-13+4x+x\left(9-x\right)$