Question

If × + y=8 & ×-y=2 , what is the value of ׳-y⁴??​

Answer 1

Step-by-step explanation:

x + y = 8_____(1)

x - y = 2_____(2)

solving Eqns (1) and (2) simultaneously:

Eqn(1) + Eqn(2)

x + x + y + (-y) = 8 + 2

2x = 10

x = 5

From Eqn (1)

y = 8 - x

y = 8 - 5 = 3.

Hence;

x^3 - y^4 = 5^3 - 3^4

= 125 - 81 = 44.