Question

find the value of x3+y3+15xy-125 if x+y=5

Answer 1

x³+y³+15xy-125
=x³ + y³ +3 xy ×5 - 125
=x³ + y³ +3xy(x+y) - (5)³
= (x+y) ³ - (5)³
=(5)³ - (5)³
=0...(ans)
Hope this is ur required answer.

Answer 2

Answer:

The value of x³+y³+15xy-125

The value of x³+y³+15xy-125= 0

Step-by-step explanation:

Given x+y = 5 ---(1)

On cubeing both sides of the equation (1), we get

(x+y)³ = 5³

=> x³+y³+3xy(x+y)=125

=> x³+y³+3xy(5)=125

/* from(1)*/

=> x³+y³+15xy = 125

=> x³+y³+15xy-125 = 0

Therefore,

The value of x³+y³+15xy-125

= 0

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