I reallly need help with this! Plase if you can

Achemist has 200 ml of a 10% sucrose solution. she adds x ml of a 40% sucrose solution. the percent concentration, y, of the final mixture is given by the rational function: the chemist needs the concentration of the final mixture to be 30%. how many milliliters of the 40% solution should she add to the 10% solution to get this concentration?

For which pair of functions is (gof)(a)=|a|-2?

Which of the following tables represents exponential functions?