What is the qoution of 2/3 and 5/6

What's the difference between: x≥0 and nonnegative integer. ?

Y=21.95x+10 y=22.45x solve by substitution

The graph of f(x) is obtained by reflecting the graph of f(x)=-3|x| over the x-axis. which equation describes f(x)? a) f(x)=3|x| b) f(x)=|x+3| c) f(x)=-3|x| d) f(x) = - |x+3|