Evaluate f-g+(-2)f−g+(−2)f, minus, g, plus, left parenthesis, minus, 2, right parenthesis where f = -3.005f=−3.005f, equals, minus, 3, point, 005 and g = 4.7g=4.7g, equals, 4, point, 7.Solve for m: Khan Academy BTW

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of