Question

find and correct the error of (2x+5)²=4x²+25​

Answer 1

Answer:

USING IDENTITY (A+B)² = A² + B² + 2AB

LHS = 4X²+25+20X

RHS = 4X²+25

THE ERROR IS THAT IDENTITY IS NOT USED(20X)

SINCE 4X²+25+20X IS NOT EQUAL YO 4X²+25

LHS IS NOT EQUAL TP RHS

Answer 2

Answer:

4x^2 + 25 =

{(2x)^2 + (5)^2}=

Now,a² + b²= (a+b)²- 2ab.

So, {(2x)^2 + (5)^2} = (2x+5)^2-(2×2x×5)

=(2x+5)²-20x