Benedict paid $7.50 for 3 similar erasers and 3 similar pens. Each pen cost $0.80 more than each eraser. How much did each pen cost?

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.

43lbs of tomatos cost $387. how much would 41lbs cost

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