What is the approximate circumference of a semicircle with a radius of 6 centimeters? 18.8 centimeters 37.7 centimeters 75.4 centimeters 150.7 centimeters

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.

Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.

The suare root of 9x plus 7 plus the square rot of 2x equall to 7