Question

if
x-y-14 and xy - 21 then the value of x²-y*
is​

Answer 1

Answer:

answer- 316

Step-by-step explanation:

Given, x−y=4 and xy=21 ...(i)

(x−y)

2

=4

2

⇒x

2

+y

2

−2xy=16

⇒x

2

+y

2

−2×21=16 (from (i))

⇒x

2

+y

2

=16+42=58

Now, x

3

−y

3

=(x−y)(x

2

+y

2

+xy)

=(4)(58+21)=316 (from(i))

Option B is correct.