How many L of a 40% alcohol solution must be mixed with 6 L of a 50% alcohol solution to make a 46% solution
+23246 (percent x amount) + (percent x amount) = final percent x final amount
0.40 · x + 0.50 · 6 = 0.46 · (x + 6) [x is the unknown number of liters of the 40% solution]
0.40x + 3.00 = 0.46x + 2.76
subtract 0.40x from both sides: 3.00 = 0.06x + 2.76
subtract 2.76 from both sides: 0.24 = 0.06x
divide both sides by 0.06: 4 = x
