Question

if 9 X square + 25 y square is equals to 181 and xy is equal to minus 6 find the value of 3 X + 5 y ​

Answer 1

Answer: 3x+5y=13

Step-by-step explanation:if 9x^2+25y^2=11

Then   x^2+y^2= (x+y)^2 - 2xy

= 3x+5y^2 - 2(-6)=181

= (3x+5y)^2 +12=181

= (3x+5y)^2=181-12

= (3x+5y)^2=169

= 3x+5y=square root of 169

=13

: 3x+5y=13

Answer 2

Step-by-step explanation:

Given:−

❒ 9x² + 25y² = 181

❒ xy = -6

Find:−

❒ Value of (3x + 5y)

Solution:−

we, have

⇁9x² + 25y² = 181 〘Given〙

Taking L.H.S

↦9x² + 25y² = (3x)² + (5y)²

➠(3x + 5y)²

★using {(a + b)}^{2} = {a}^{2} + 2ab + {b}^{2}

➠(3x)² + 2(3x)(5y) + (5y)²

➠9x² + 30xy + 25y²

★Rearranging The Term★

➠9x² + 25y² + 30xy

★ using 9x^{2} + 25 y^{2} = 181

➠181 + 30xy

★now, using xy = - 6

➠181 + 30(-6)

➠181 + (-180)

➠181 - 180

➠1

⇨3x + 5y = 1

Hence, answer is 1