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Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

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.

X+ y = 5 ; x - y =3 solve using linear combination