Question

x-y=4 and xy=12 find the value of x^3-y^3

Answer 1

↑ Here is your answer ↓
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$x - y = 4$

$x = y+4 --(1)$

$xy = 12 --(2)$

Sub (1) in (2)

$y(y+4) = 12$

$y^2 + 4y - 12 = 0$

$y^2 + 6y - 2y - 12 = 0$

$y(y+6) - 2(y+6) = 0$

$(y-2)(y+6) = 0$

Lets take y = 2

Use (2) now

$xy = 12$

$2x = 12$

$x = 12/2$

$x = 6$

Now

$= x^3 - y^3$

$= 6^3 - 2^3$

$=216 - 8$

$=208$

Answer 2

-112 is the answer of your question