Question

11. If x^2+ y^2 = 13 and x*y = 6, find the value of the following.
i. x+y
ii. X-y
iii. x^4 + y^4​

Answer 1

Step-by-step explanation:

1) x²+y²= 13,

add 2xy on both sides,

x²+y²+2xy = 13+2xy

(x+y)²= 25

x+y = 5

2) subtract 2xy in both sides

x-y= 1

3) (x²+y²) = 13

squaring both sides,

x⁴+y⁴+2(xy)² = 169

x⁴+y⁴= 97