Solve the problem.
-$$( 9 r - 10 ) ( 9 r + 10 )$$
A) $9 r ^ { 2 } - 100$
B) $81 + 180 \mathrm { r } - 100 \mathrm { r } ^ { 2 }$
C) $81 r ^ { 2 } - 100$
D) $81 r ^ { 2 } - 180 r - 100$

Question

Quizplus · Accepted Answer

This problem uses the difference of squares formula, $a^2 - b^2 = (a - b)(a + b)$. Here, $a = 9r$ and $b = 10$, so the expression simplifies to $(9r)^2 - (10)^2 = 81r^2 - 100$.

Solve the Problem (9r−10)(9r+10)( 9 r - 10 ) ( 9 r + 10 )(9r−10)(9r+10)

Solve the Problem $( 9 r - 10 ) ( 9 r + 10 )$