The number in the photo should be the answer but the problem might just be that your question was worded incorrectly.
Answer:
We must add 400 ml of water.
Step-by-step explanation:
We can use the following equation:

Where:
- C(i) is the initial concentration of the solution (80%)
- C(f) is the final concentration of the solution (30%)
- V(i) is the initial volume (150 ml)
- V(f) is the final volume
Now, we just need to solve the equation for V(f).



Therefore, we must add 400 ml of water.
I hope it helps you!
Answer:
Your score is 100.
Step-by-step explanation:
If you have -300 and add +300 you will end up with 0 because when a positive and a negative that are equal cancel each other out. So if you add +300 to -300 you get 0 but its 400 so 300 + 100 is 400 so you have +100 left. : )
The statement <span>The coefficient of x^k y^n-k in the expansion of (x+y)^n equals (n-k / k) is true. This will show the standard formula and the expansion of it. We all know that it can still be expanded based on the power or degree of the terms.</span>