Factor completely. Check by multiplying the factors. $49 x ^ { 2 } - 100 y ^ { 2 }$
A) $( 7 x - 10 y ) ( 7 x - 10 y )$
B) $( 7 x - 100 y ) ( 7 x + 1 y )$
C) $( 7 x + 10 y ) ( 7 x + 10 y )$
D) $( 49 x - 10 y ) ( 1 x + 10 y )$
E) $( 7 x - 10 y ) ( 7 x + 10 y )$

Question

Quizplus · Accepted Answer

We can use the formula for the difference of squares which is $a^2-b^2=(a+b)(a-b)$. Let $a=7x$ and $b=10y$ then we have $49x^2-100y^2=(7x)^2-(10y)^2=(7x+10y)(7x-10y)$. Therefore, the answer is $\boxed{	extbf{(E)}\ (7x-10y)(7x+10y)}$.

Factor Completely 49x2−100y249 x ^ { 2 } - 100 y ^ { 2 }49x2−100y2

Factor Completely $49 x ^ { 2 } - 100 y ^ { 2 }$