Add. (2x3+5x−16)+(4x3−10x2−2x)

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 two square pyramids are similar. find the total volume of both pyramids if the ratio of their surface areas is 9/16

Donald has x twenty-dollar bills and 11 ten-dollar bill. how much money does donald have? write your answer as an expression.