Answer:
1L of 30% fertilizer and 9L of 10% fertilizer
Step-by-step explanation:
Let x = the amount of fertilizer containing 30% nitrogen.
Let y = the amount of fertilizer containing 10% nitrogen
x + y = 10 because the two fertilizers together will be 10L
0.3x will be the amount of nitrogen in the 30% nitrogen fertilizer, and 0.1y will be the amount of nitrogen in the 10% fertilizer. If you add those together, you will get 12% of the nitrogen in the 10L mixture. This makes this equation:
0.3x + 0.1y = 0.12(10)
0.3x + 0.1y = 1.2
Now we have our two equations.
x + y = 10
0.3x + 0.1y = 1.2
We can use substitution to solve this system of equations.
x = 10 - y
Substituting this into the second equation, we have:
0.3(10-y) + 0.1y = 1.2
3 - 0.3y + 0.1y = 1.2
3 - 0.2y = 1.2
1.8 = 0.2y
9 = y
10 - 9 = 1L
There will be 9L of 10% nitrogen fertilizer and 1L of 30% nitrogen fertilizer.
