If a diagonal of a square is 11.3 meters, approximately what is the perimeter of the square

Its due ! write an equation in which the quadratic expression 2x^2-2x 12 equals 0. show the expression in factored form and explain what your solutions mean for the equation. show your work.

If f(x) = x+8 and g(x) = 4x- 3, find (f+g)(x)

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.