Evaluate 6 + 3b if b = 7

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?

Can someone pls ! pls answer all. no explanation needed..

Ann and betty together have $60 ann has $9 more than twice betty’s amount how much money dose each have