Question

find x^3+y^3-12xy+64 when x+y=4

Answer 1

i think x+y= (-4) else it won't be solved

Answer 2

x³ + y³ - 12xy + 64

(x)³ + (y)³ - 3(x)(y)(4) + (4)³

$<b>Using a³ + b³ + c³ - 3abc = ( a + b + c ) ( a² + b² + c²- ab - bc -ca )</b>$

( x + y + 4 ) ( x² + y² + 4² - xy - y4 - 4x )

( x + y + 4 ) ( x² + y² + 16 - xy - 4y - 4x )

$<b>Hey friend ( x + y ) should be - 4 or answer will not come.</b>$

We know ( x + y ) = -4

So ( - 4 + 4 ) ( x² + y² + 16 - xy - 4y - 4x )

( 0 ) ( x² + y² + 16 - xy - 4y - 4x )

= 0

$Please \: mark \: this \: answer \: as \: the \\ BRILLIANIST\\ ANSWER.$