Question

if X3+y3 =16 and x+y=8 then (x-y)is ____​

Answer 1

Answer:

x+ y =8 (1)

x*y=6 (2)

Solving equation 2 fro x as

x=6/y (3)

Putting the value of x in (1)

x+ y=8

6/y+ y=8

(6+y^2)/y=8

6+y^2=8y

y^2-8y+6=0

Using quadratic formula

y=(-(-8)±√(-8_^2)-4 (1)(6))/2(1)

y=(8±√64-24)/2

y=(8±√40)/2

y=(8±2√10)/2

y=4±√10

Put the value of y in (1)

x+y=8

x+4±√10=8

x=8-4±√10

x=4±√10

So x=4±√10 and y=4±√10