The sum of an even number and an odd number is always an even number ? true or false ? if so why

Solve the system of equations. y= 2x y= x^2 - 15

Simplify the expression. -2/5(10+15m-20n)

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?