every time i take a picture of the equation and try to click solve it doesn’t pick up the “plus or minus” sign so pls help so i get the correct answer

One side of a rectangle is 7 feet shorter than seven times the other side. find the length of the shorter side if we also know that the perimeter of the rectangle is 306 feet.

Is this a polynomial function? i need to know asap

Which expression do you get when you eliminate the negative exponents of 4a^2 b^216a^-3 b