Question

2.
If 3x + 4y = 18 and xy = 6, find the value
9x² + 16y²
(A) 180
(B) 144
(C) 324
(D) 170​

Answer 1

Answer:

Answer is (A)180

Step-by-step explanation:

As we know that,, 3x+4y = 18.

xy = 6.

Let's find the answer,,,

3x+4y = 18

; (3x+4y)^2 = (18)^2. (squaring both the

sides)

; 9x^2 + 16y^2 + 24xy = 324.

; 9x^2 + 16y^2 + (24×6) = 324 [xy = 6,

(Given)]

; 9x^2 + 16y^2 + 144 = 324.

; 9x^2 + 16y^2 = 324-144.

; 9x^2 + 16y^2 = 180.