Question

If x-y=7 and xy= 9 find the value of x⁴+y⁴

Answer 1

Answer:

4327

Step-by-step explanation:

x-y=7    xy=9     x^4+y^4

s.o.b.s

(x-y)^2=7^2

x^2- 2 xy + y^2 =49

x^2 - 18+y ^2=49

x^2+y^2=49+18

x^2+y^2=67

again s.o.b.s

(x^2+y^2)^2=67^2

x^4+y^4+2 (xy)^2 =4489

x^4+y^4+162=4489

x^4+y^4=4489-162

x^4+y^4 =4327