Simplify the expression. write your answer without negative exponents. assume that the variables represent nonzero real numbers

Suppose that sahil knows that 45 people with ages of 18 to 29 voted. without using a calculator, he quickly says then 135 people with ages of 30to 49 voted. is he correct? how might sohil have come up with his answer so quickly?

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?

y=2x−1 5x−4y=1 is (1,1)(1,1) a solution of the system?