Question

Simplify. (2m + 5)^2 – (2m – 5)^2 = ?​

Answer 1

Answer:

40m is the answer

Step-by-step explanation:

(2m + 5)^2 – (2m – 5)^2

= [(2m+5)+(2m-5)][(2m+5)-(2m-5)]

= (4m+5-5)(2m-2m+10)

= 4m(10)

= 40m is the answer

The identity used above is

a^2-b^2=(a+b)(a-b)

Here a = (2m+5) ; b = (2m-5)