Let x represent the amount to be added. The total amount of tin will be
15%·20 + 10%·x = 12%·(20+x)
(15%-12%)·20 = (12%-10%)·x
3%·20/2% = x
30 = x
30 pounds of 10% tin must be added to get a 12% mixture.
3x=18 because you add the like terms 6 and 12
Answer:
2x=1
Step-by-step explanation:
Use x for "a number"
x times 2 = 1
2x=1
which solves for 0.5 or 1/2
