Question

If 3x+ 2y=9 and xy=3, find the value of (9x²+ 4y²)​

Answer 1

Answer:

Step-by-step explanation:

Answer

3x+2y=12

Squaring both sides, we get

(3x+2y)

2

=144

⇒9x

2

+4y

2

+2×3x×2y=144

⇒9x

2

+4y

2

=144−12xy

⇒9x

2

+4y

2

=144−12×6 since xy=6

⇒9x

2

+4y

2

=144−72=72

∴9x

2

+4y

2

=72