The size of a certain cell is 2.5×10−9m. Another cell is 8.5×103m times larger. How large is the larger cell in scientific notation? PLEASE HELP ME

What number should be added to both sides of the equation to complete this square? x^2-10x=7

Me with this assignment ! i only partially understand, so explain. also it's a work sample. at the championship bike race, steve and paula were fighting for first place. steve was 175 feet ahead of paula and had only 300 feet left to go. he was very tired and was going only 9 feet per second. paula was desperate to catch up and was going 15 feet per second. who won the bike race and by how far did she/he win?

Heather is a cashier. she can ring up 1212 customers in 99 minutes. at this rate, how many minutes does it take her to ring up 44 customers?