Write 8% as a decimal

On a piece of paper graph f(x)=5•(0.4)^x

Show your workcan a right triangle have this sides? *how to prove it without using the pythagorean theorema*

Given that y varies directly to the square root of (x + 1), and that y = 1 when x = 8,(a)express y in terms of .x,(b)find the value of y when x = 3,(c)find the value of x when y = 5.