Let y=x+6 be equation 1...
Replace equation 1 in equation 2
X+6 =-2x-3
X+2x = -3 -6
3x = -9
X = -3
8 litres (amount of 20% solution needed) and 7 litres for (amount of 50% solution needed)
<u>Step-by-step explanation:</u>
Let consider ‘x’ for 20% acid solution and (15 – x) for 50% acid solution. And so, the equation would be as below,
20% in x + 50% in (15 – x) = 15 litres of 34%
Convert percentage values, we get
0.20(x) + 0.50 (15 – x) = 15 (0.34)
0.20 x + 7.5 – 0.50 x = 5.1
-0.3 x + 7.5 = 5.1
0.3 x = 7.5 – 5.1
0.3 x = 2.4

Apply ‘x = 8’ value in (15 – x) we get,
15 – 8 = 7 litres
The value of 7 litres for (amount of 50% solution needed)
The number of bats that there would be in 2021 would be 768,000.
<h3>What would be the number of bats in 2021?</h3>
The formula that can be used to determine the future value of bats in 2021 is:
FV = P (1 + r)^n
Where:
- FV = Future value
- P = Present value = 3000
- R = interest rate = 300%
3000(1 + 3)^4
3000 x 4^4 = 768,000
To learn more about future value, please check: brainly.com/question/18760477
A. Imagine the circle has a radius of 3 and height of 9. 3 x 9 = 27/3 is 9. If radius is doubled that’s 6 and height is tripled would make it 27. So 6 x 27 is 162 divided by 3 is 54 and 9 x 6 is 54
Answer:
6.66 hours, that is, 6 hours and 40 minutes.
Step-by-step explanation:
If Mike can plow a field in 12 hours, we plows 1/12 of the field each hour.
If Phil can plow a field in 15 hours, we plows 1/15 of the field each hour.
So if they are working together, they can plow (1/12) + (1/15) of the field each hour, that is:
(1/12) + (1/15) = (5 + 4) / 60 = 9 / 60 = 3 / 20 = 1 / 6.66
So if they work together, they can plow the field in 6.66 hours, that is, 6 hours and 40 minutes.