Answer:
21x -14y -63
Explanation:
First step we have to distribute -7 inside the parenthesis.
(-7)(2y) - (-7)(3x) +(-7) (9)
RULE 1: The product of a positive integer and a negative integer is negative. RULE 2: The product of two positive integers is positive.
RULE 3: The product of two negative integers is positive.
-14y+ 21x - 63
21x -14y -63