Question

$find \: the \: value \: of \: 8 {x}^{3} + {y}^{3} - 30xy + 125 \: if \: 2x + y = - 5$
spams stay away. Unwanted answers will be reported.​

Answer 1

Answer:

Given:

• 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

Hope it helps! ❤