Arectangle has a length of 3x inches. the width of the rectangle is (2x+6) inches more than the length. a) find the perimeter of the rectangle in terms of x. b) if x=3, find the perimeter of the rectangle.

The average human heart beats 1.15 \cdot 10^51.15⋅10 5 1, point, 15, dot, 10, start superscript, 5, end superscript times per day. there are 3.65 \cdot 10^23.65⋅10 2 3, point, 65, dot, 10, start superscript, 2, end superscript days in one year.how many times does the heart beat in one year? write your answer in scientific notation, and round to one decimal place.

The figures below are made out of circles, semicircles, quarter circles, and a square. find the area and the perimeter of each figure and give your answers as a completely simplified exact value in terms of π (no approximations).

What does independent variable and dependent variable mean in math?