Question

If 5x – 2y = 7 and xy = 2, find the value of (5x + 2y)^2​

Answer 1

Answer:

Consider the given equation,

5x−2y=7 and xy=2

We have to find (5x+2y)

2

=?

Now,

(5x−2y)

2

=25x

2

+4y

2

−20xy

7

2

=25x

2

+4y

2

−20×2

25x

2

+4y

2

=89

Now,

(5x+2y)

2

=25x

2

+4y

2

−20xy

(5x+2y)

2

=89−20×2

(5x+2y)

2

=49

Hence, this is the answer.