Question

Q 4 Using suitable identity find (7x - 3y)²?.​

Answer 1

Answer:

We know (a+b)

2

=a

2

+2ab+b

2

By using this identity, we get

(7x+3y)

2

=(7x)

2

+(3y)

2

+2×7x×3y

=49x

2

+9y

2

+42xy

This is the required answer.

Answer 2

Answer:

we know that ( a-b ) ² = a²+b²-2ab

so (7x-3y) ²

14x²+9y²-21xy answer