Question

find the value of 4x^2+9y^2 if 2x + 3y=18 and xy= 5​

Answer 1

${\huge{\green{\underline{\underline{\sf {\mathfrak{Answer}}}}}}}$

${\bf{\orange{\underline{Given:}}}}$

• $2x+3y=18$
• $xy=5$

${\bf{\orange{\underline{Solution:}}}}$

$\implies 2z+3y = 18$

$\implies (2x+3y)^2 = 18^2$

$\implies 4x^2 + 9y^2 + 12xy = 324$

$\implies 4x^2 + 9y^2 + 12(5) = 324$

$\implies 4x^2 + 9y^2 = 324 - 60$

$\green{\boxed{\implies{\boxed{4x^2 + 9y^2 = 264}}}}$

Answer 2

Answer:

2x + 3y = 18

xy = 5

(2x + 3y)^2 = 4x^2 + 2*2x*3y + 9y^2

18^2 = 4x^2 + 12xy + 9y^2

324 = 4x^2 + 12*5 + 9y^2

324 = 4x^2 + 60 + 9y^2

4x^2 + 9y^2 = 162

Step-by-step explanation: