SOLUTION: To make 10 kg of aluminum alloy with 60% aluminum, a scientist wants to use two metals with 45% and 70% aluminum content respectively. How much of each metal should she use? (Hint:

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: To make 10 kg of aluminum alloy with 60% aluminum, a scientist wants to use two metals with 45% and 70% aluminum content respectively. How much of each metal should she use? (Hint:      Log On


   

Question 172456: To make 10 kg of aluminum alloy with 60% aluminum, a scientist wants to use two metals with 45% and 70% aluminum content respectively. How much of each metal should she use? (Hint: The amount of aluminum in the alloy is the sum of the amounts in the original meatls.)
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
lets call the amount of metal for the 45% and 70%, a and b respectively
:
a+b=10............eq 1
.45a+.7b=.6(10)...eq 2
:
rewrite eq 1 to b=10-a and plug b's value into eq 2
:
.45a+.7(10-a)=6
:
.45a+7-.7a=6
:
.25a=1
:
highlight%28a=4%29kg
highlight%28b=10-4=6%29kg