Answer the question.
-$$[ ( 5 x - y ) + 3 z ] [ ( 5 x - y ) - 3 z ]$$
A) $25 x ^ { 2 } - 10 x y + y ^ { 2 } - 9 z ^ { 2 }$
B) $25 x ^ { 2 } + y ^ { 2 } - 9 z ^ { 2 }$
C) $25 x ^ { 2 } + y ^ { 2 } + 30 x z + 6 y z - 9 z ^ { 2 }$
D) $25 x ^ { 2 } - 10 x y + y ^ { 2 } + 30 x z + 6 y z - 9 z ^ { 2 }$

Question

Quizplus · Accepted Answer

This expression is an example of the difference of squares formula, $a^2 - b^2 = (a + b)(a - b)$. Here, $a = 5x - y$ and $b = 3z$. Squaring both gives $25x^2 - 10xy + y^2$ for $a^2$ and $-9z^2$ for $-b^2$, leading to the correct answer.

Answer the Question [(5x−y)+3z][(5x−y)−3z][ ( 5 x - y ) + 3 z ] [ ( 5 x - y ) - 3 z ][(5x−y)+3z][(5x−y)−3z]

Answer the Question $[ ( 5 x - y ) + 3 z ] [ ( 5 x - y ) - 3 z ]$