0.0000078

convert to scientific notation

Hey free points ! people i have a few math questions on my profile consider looking at them i have to get done in 30 mins!

Determine which postulate or theorem can be used to prove that lmn =nmo

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )