Question

3x+ 4y= 16 and xy =2 then 9x2+16y2​

Answer 1

Answer:

3x+4y = 16

squaring both side

(3x+4y)2= (16)2

9x2+16y2+12xy = 256

9x2+16y2+12(2)= 256

9x2+16y2+24= 256

9x2+16y2 = 232

Answer 2

Answer:

208

Explanation:

xy =2------>1

3x+ 4y= 16---->2

squaring on both sides

(3x+4y)^2=16^2

=> 9x^2+16y^2+ 24 xy= 256

=> 9x^2+16y^2+ 24 (2) = 256 ( from 1

=> 9x^2+16y^2+ 48 = 256

=> 9x^2+16y^2 = 256 - 48

=> 9x^2+16y^2 = 208