Answer:
495 milliliters of the 95% mixture are needed.
Step-by-step explanation:
Given that I need a 90% alcohol solution, and on hand I have a 55 ml of a 45% alcohol mixture, and I also have 95% alcohol mixture, to determine how much of the 95% mixture will I need to add to obtain the desired solution, the following calculation must be performed:
55 x 0.45 + 45 x 0.95 = 67.5
25 x 0.45 + 75 x 0.95 = 82.5
15 x 0.45 + 85 x 0.95 = 87.5
10 x 0.45 + 90 x 0.95 = 90
10 = 55
90 = X
90 x 55/10 = X
4,950 / 10 = X
495 = X
Thus, 495 milliliters of the 95% mixture are needed.
You want to find
meters per second.So meters goes over seconds

Now pull out the calculator.
You should get ≈

, or 7.4 meters per second
Answer:
The answer is 231
Step-by-step explanation:
Answer:
10 cm
Step-by-step explanation:
If we assume that DC is parallel to AB, then triangle DOC is similar to triangle AOB.
However, even with this assumption, there is not enough information in the diagram to solve for DO. We would also need to know the length of CO. Then we could write a proportion:
DO / (DO + 20) = CO / (CO + 24)
Edit: OD is 2 cm shorter than OC. If we call x the length of OD, then the length of OC is x+2.
Putting this into our proportion:
x / (x + 20) = (x + 2) / (x + 2 + 24)
x / (x + 20) = (x + 2) / (x + 26)
Cross multiply:
x (x + 26) = (x + 2) (x + 20)
Distribute:
x² + 26x = x² + 20x + 2x + 40
x² + 26x = x² + 22x + 40
4x = 40
x = 10
So the length of DO is 10 cm.
Answer:
-3b - 21
Step-by-step explanation:
You have distribute the -3 to both b and 7. So, you would have to multiply the -3 to both b and 7.