Arectangle has an area of 228ft and a length that measures 12 ft find the perimeter of the rectangle

Quick translate "x is 12 units from 20" into an equation. what are the values of x being described? if you can answer any of my other questions that'd be great too

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.

Factor the trinomial below. 12x^2 - 32x - 12 a. 4(3x+3)(x-1) b. 4(3x+1)(x-3) c. 4(3x+6)(x-2) d. 4(3x+2)(x-6)