Which transformation is non isometric transformation

Which of the following is correct interpretation of the expression -4+13

Atriangle has an area of 72 square inches. if the base of the triangle has a length of 18 inches, what is the height of the triangle? use the formula for the area of a triangle: area = (base)(height) type a numerical answer in the space provided. do not include the units or spaces in your answer.

Bring the fraction a/a-4 to a denominator of 16-a^2