Please help me!!! I need help finding the angles for these:

Write the expression 7x^3-28xy^2 as the product of 3 factors

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

Determine the required value of the missing probability to make the distribution a discrete probability distribution. x p(x) 3 0.23 4 ? 5 0.51 6 0.08 p(4) = nothing  (type an integer or a decimal.)