Please help i don’t know how to do this

For f(x)=2x+3 and g(x)=x^2- 8 find (f+g) (x)

Each cookie sells for $0.50 sam spent $90 on baking supplies and each cookie cost $0.25 to make how many cookies does sam need to sell before making a profit formula: sales> cost

Which number completes the inequality? 2/3 < _ < 7/9