Question

Find 4x2+9y2 if 2x +3y=18&xy=5​

Answer 1

Hey there !!!

2x+3y=18-------------Equation 1

squaring Equation 1

(2x+3y)²=18²

4x²+2*2x*3y+9y²=18²

4x²+9y²+12xy=324

But given that xy=5

So,

4x²+9y² =324- 12*5

4x²+9y²= 324-60 = 264

Hope this helped you..................

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