Multiply using one of the rules for the square of a binomial. Assume any variable exponents represent whole numbers.
-$$( 3 x - 7 y ) ^ { 2 }$$
A) $9 x ^ { 2 } - 42 x y + 49 y ^ { 2 }$
B) $3 x ^ { 2 } + 49 y ^ { 2 }$
C) $3 x ^ { 2 } - 42 x y + 49 y ^ { 2 }$
D) $9 x ^ { 2 } + 49 y ^ { 2 }$

Question

Quizplus · Accepted Answer

The square of a binomial $(a - b)^2$ is given by $a^2 - 2ab + b^2$. Applying this to $(3x - 7y)^2$, we get $9x^2 - 2(3x)(7y) + 49y^2 = 9x^2 - 42xy + 49y^2$.

Multiply Using One of the Rules for the Square of a Binomial