Free points day #2 have a great day

Find the sum of 4x^{2} -4+6 and -7^{2} +3x+1

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.

Solve for x: 5/3 x = 20/21 it's fraction. remember to simplify your fraction