Question

if 3 X + 7 Y is equals to 20 and x y is equals to 4 then value of 9 X square + 49 y square is ​

Answer 1

Answer:

232

Step-by-step explanation:

on squaring 3x+7y =20

${(3x + 7y)}^{2} = 400 \\ 9 {x}^{2} + 49 {y}^{2} + 42xy = 400 \\ 9 {x}^{2} + 49 {y}^{2} + 168 = 400 \\ 9 {x}^{2} + 49 {y}^{2} = 232$