Question

if x²+1/x²=23, find the value of 8x3-27y3+90xy+115​

Answer 1

Answer:

2x=3y−5

2x−3y=−5

Now let us cube on both sides, we get

(2x−3y)

3

=(−5)

3

(2x)

3

−(3y)

3

−3×2x×3y(2x−3y)=−125

8x

3

−27y

3

−18xy(2x−3y)=−125

No, substitute the value of 2x−3y=−5

8x

3

−27y

3

−18xy(−5)=−125

8x

3

−27y

3

+90xy=−125

8x

3

−27y

3

+90xy+125=0