How to make a for loop for fzero solved functions?

Im having some issues making a loop for fzero functions. Basically I want a code that solves for x(i+1) and then uses that value to solve for the next equation

function y=fncsys(x)
x(1)=0.3
y=0
for i=1:4
y = 5(x(i)-x(i+1)) +10((x+i)^2)
end
fzero(@fncsys, 1)