How much fertilizer containing 30% nitrogen should be mixed with a fertilizer containing 10% nitrogen to get 10L of a fertilizer containing 12% nitrogen?

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.

you never say the total so we cant find the percentage used for petrol

step-by-step explanation: