Solve using elimination
-x-9y=10
-x+6y=-5

True or false? a triangle can be circumscribed about a given circle

Solve - pv + 40 < 65 for v solve 7w - 3r = 15 for r

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?