Factor each trinomial completely 21x^2-35x-14

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?

Pls never taught i’m really confused and i rlly need

Last week jason walked 3 1/4 miles each day for 3 days and 4 5/8 miles each day for 4 days. about how many miles did jason walk last week?