Add and simplify. Please help

Olivia uses the work below to determine 55% of 720 which explains the error in olivia’s solution

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.

Which simplifys to a+ b? a-(1-b)+1 -(1-a)-b+1 (a--1) -1)+1