Answer:
(2x-7y) (2x+7y)
Step-by-step explanation:
4x^2−49y^2
This is the difference of squares
a^2 - b^2 = (a-b) (a+b)
a^2 =4x^2 so a = 2x
b^2 = 49y^2 so b =7y
4x^2−49y^2 = (2x-7y) (2x+7y)