Question

(x + 3y)2 + (x - 3y)?​

Answer 1

Answer:

We know, (a+b)

2

=a

2

+2ab+b

2

and (a−b)

2

=a

2

−2ab+b

2

.

Then,

(x+3y)

2

+(x−3y)

2

=[(x)

2

+(3y)

2

+2×x×3y]+[(x)

2

+(3y)

2

−2×x×3y]

=x

2

+9y

2

+6xy+x

2

+9y

2

−6xy

=2x

2

+18y

2

.