Question

(4m + 5n)2+ (5m + 4n)2 + (4m + 5n) (4m -5n)

Answer 1

Solution:

Correct option is

A

41m

2

+80mn+41n

2

Given, (4m+5n)

2

+(5m+4n)

2

.

We know, (a+b)

2

=a

2

+2ab+b

2

.

Then,

(4m+5n)

2

+(5m+4n)

2

=[(4m)

2

+2(4m)(5n)+(5n)

2

]+[(5m)

2

+2(5m)(4n)+(4n)

2

]

=16m

2

+40mn+25n

2

+25m

2

+40mn+16n

2

=41m

2

+80mn+41n

2

.

Therefore, option A is correct