I need this today, sorry, also having trouble finding domain

Question

Find f + g, f - g, fg, and f/g. Determine the domain for each function.

f(x)= square root of x; g(x)= x-18

Answer 1

f+g = sqrt(x)+x-18

domain , [0,inf)

f-g = sqrt(x)-x+18

domain , [0,inf)

fg= sqrt(x)[(x-18)]

domain , [0,inf)

f/g= sqrt(x)/(x-18)

domain, [0,18)u(18,inf)