270 sectioned out by 45s is 7 toll booths on the highway. That means theres a toll booth at 0 mi, 45, 90, 135, 180, 225 and 270 mi. If Josh exits after 120 mi, he only hits the booth at the beginning and then the last one at 90 mi because he doesn't reach the next one at 135 mi. $2.75 per toll booth and if he passed 3, then 2.75 x 3 = $8.25.
Negative numbers don't have real square roots since a square is either positive or 0. The square roots of numbers that are not a perfect square are members of the irrational numbers. This means that they can't be written as the quotient of two integers.