Question

If f(1) =7 and f(n)=-5f(n-1)-n

then find the value of
f(4)

Answer 1

-914

Explanation:

f(n)=-5f(n-1)-n

f(2)= -5f(1) -2 = -5(7) - 2 = -37

f(3) = -5f(2) - 3 = -5(-37) - 3 = 182

f(4) = -5f(3) - 4 = -5(182) - 4 = -914