Mathmatics question please helppp

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

The width of a rectangle is 20 units. can the perimeter p of the rectangle be 64 units when its length x is 11 units? no, because p = 2x + 2(20) no, because p ≠ 2x + 2(20) yes, because p ≠ 2x + 2(20) yes, because p = 2x + 2(20)

Which of the following contains a variable?