What is the value of a^4-b^4?

(1) a^2 - b^2 = 16
(2) a+b = 8

(1) a^2 - b^2 = 16 (2) a+b = 8 1 and 2 (a+b)(a-b) = 16 and a + b = 8 then a - b = 2 then a = 5 and b = 3 a^4 - b^4 = 5^4 - 3^4