-m/3+6=12 this is for a quiz pls respond quick!

Find the length of the diagonal of the rectangle. round your answer to the nearest tenth. || | | 8 m | | | | 11 m

Solve each quadratic equation by factoring and using the zero product property. [tex]x^2+6x+8=0[/tex]

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.