Can someone explain the equation / formula to this question?

Given a(-12,5) and b(12,29) find the point that divides the line segment ab three-eighths of the way from a to b

Let hh represent the number of hummingbirds and ss represent the number of sunbirds that must pollinate the colony so it can survive until next year. 6h+4s > 746h+4s> 74 this year, 88 hummingbirds pollinated the colony. what is the least number of sunbirds that must pollinate the colony to ensure that it will survive until next year?

You wanted to draw an enlargement of design that printed on a card that is 4 in by 5