Question

(2x + 5)2 = (2x)2 + 52 + 2 × 2x × 5
give me correct answer!

Answer 1

Step-by-step explanation:

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

here

a=(2x+5)

b=(2x-5)

so

(2x+5) ^2-(2x-5) ^2=[2x+5-(2x-5) ][2x+5+2x-5]

=10×4x

=40x

rvk123

rvk123

It is done by (a+b)²-(a-b)²=(a²+2ab+b²)-a²-2ab+b²;

so

(4x²+2×2x×5+25)-(4x²-2×2x×5+25)

4x²+20x+25-4x²+20x-25;

Ans=40x

40x=1;

Ans=x=1/40