A metalworker has a metal alloy that is 15% copper and another alloy that is 70% copper. How many kilograms of each alloy should the metalworker combine to create 50 kg of a 59% copper alloy?
The metalworker should use__kilograms of the metal alloy that is copper and___kilograms of the metal alloy that is 70% copper
Let x be the number of kilograms of the 15% copper alloy.
Thus, the number of kilograms for the 70% copper alloy is 50 - x.
The total amount of copper in the 15% copper alloy is 0.15x kg.
The total amount of copper in the 70% copper alloy is 0.70(50 - x) kg.
The total amount of copper in the final alloy is 0.59(50) kg.
So, the equation for the total amount of copper is 0.15x + 0.70(50 - x) = 0.59(50).
Simplifying the equation gives 0.15x + 35 - 0.70x = 29.50.
Combining like terms gives -0.55x + 35 = 29.50.
Subtracting 35 from both sides gives -0.55x = -5.50.
Dividing both sides by -0.55 gives x = 10.
Therefore, the metalworker should use 10 kilograms of the 15% copper alloy and 40 kilograms of the 70% copper alloy. Answer: \boxed{10, 40}.