Question

20. If x + y = 5,( x + y )^3= 35, find the value of x - y.​

Answer 1

Answer:

1

Step-by-step explanation:

(x+y)

3

=x

3

+y

3

+3xy(x+y)

or 5

3

=35+3xy(5)

or 125−35=15xy

or xy=

15

90

=6

Now, (x−y)

2

=(x+y)

2

−4xy

=5

2

−4×6

=25−24=1

∴x−y=

1

=±1