I need help with these (need to show work too)

What is the distance from zero if a quadratic function has a line of symmetry at x=-3 and a zero at 4

Will mark ! (10 points also! ) if x varies inversely with y and x =6 when equals y= 10, find y when x=8 a. y=4.8 b. y=7.5 c. y=40/3 d. y=4/15

To find the inverse of a number a, one can use the equation f(c) = a-1/c=0 where c is the inverse of a use the secant method of finding roots of equations to find the inverse of a = 2.5 ,er = 0.001%