Answer:

Step-by-step explanation:
x-7y = -49
i) move x to the right-hand side and change its sign
-7y = -49-x
ii) change the signs on both sides of the equation
7y = 49+x
iii) divide both sides of the equation by 7


iv) use the commutative property to reorder the terms
* commutative property: a+b = b+a

The volume of the water storage tank is the amount of space in it
The volume of the water storage tank is 6468 cubic feet
<h3>How to determine the volume?</h3>
The given parameters are:
Radius (r) = 21 feet
Height (h) = 14 feet
The shape of the water storage tank is a cone.
And the volume of a cone is:
V = 1/3πr^2h
So, we have:
V = 1/3 * 22/7 * 21^2 * 14
This gives
V = 6468
Hence, the volume of the water storage tank is 6468 cubic feet
Read more about volumes at:
brainly.com/question/1972490
Let's say that the value invested in the account with a rate of 8% is "x", then the amount invested in the account with a rate of 12% is:

To calculate the total interest we need to calculate the interest of each individual account and sum them:

The total interest is the sum of the two expressions above:

The value invested in the account with 8% interest is 830, the one invested in the account with 12% interest is 1280.