Help me please ASAP thank you you

Describe the 2 algebraic methods you can use to find the zeros of the function f(t)=-16t^2+400.

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

At your job you're paid $50 per week plus $3 per sale at least how many saled do you need to make in order to have over $250