91Ó°ÊÓ

Simplify. Assume that all variables represent nonzero integers. $$ \frac{25 x^{a+b} y^{b-a}}{-5 x^{a-b} y^{b+a}} $$

Write an equivalent expression using a commutative law. Answers may vary. $$ (7 x) y $$

Write an equivalent expression using an associative law. $$ (3 x) y $$

Write an equivalent expression using the distributive law. $$ 3(a+5) $$

Find an equivalent expression by factoring. $$ 9 p-3 $$

Find an equivalent expression by factoring. $$ 7 x-21 y+14 z $$

Find an equivalent expression by factoring. $$ 6 y-9 x-3 w $$

Find an equivalent expression by factoring. $$ a b+b $$

Describe in your own words a method for determining the sign of the sum of a positive number and a negative number.

Insert one pair of parentheses to convert each of the following false statements into a true statement. $$ 8-5^{3}+9=36 $$