Question

If 2x + 3y = 8 and xy = 2, then find the value of 4x^2 + 9 y^2.​
Step by step explain

Answer 1

Answer:

given:- 2x+3y = 8

xy = 2

4x² + 9y² = ?

Lets use the identity,

(a+b)² = a² + b² +2ab

(2x +3y)²= (2x)²+(3y)²+2×2x×3y

= 4x²+9y²+12xy

(bring 4x²+9y² to R.H.S.)

4x²+9y²=12xy

(given xy = 2)

thus,4x² + 9y²=12×2

4x²+9y²=24