Question 465029
0.01x + 0.04(5 - x) = 0.02*5

<==> 0.01x + 0.2 - 0.04x = 0.1
<==> -0.03x = -0.1
<==> x = 10/3 gallons of 1%, and 
5 - x = 5/3 gallons of 4%.