<span>Answer:
The multiplication factor of increase should be inverse of the multiplication factor of decrease.
e.g. Say you have a number 100.
You increase it by 25%. The multiplication factor is 5/4 i.e. when you multiply 100 by 5/4, you get 100*5/4 = 125. This is 25% more than 100.
Now you want to decrease it by a certain % such that you get 100 back.
Basically, 100*5/4 * x = 100
So x = 4/5 (inverse of 5/4)
Hence, you decrease by 20% (the multiplication factor of 20% is 4/5)
or
Use this formula: cumulative % change = a + b + ab/100
You want the cumulative change to be 0.
a + b + ab/100 = 0
If you know that you are increasing by 25% and want to find the % by which you should decrease to get the same number,
25 + b + 25b/100 = 0
5b/4 = -25
b = -20
So you need to decrease (hence you get the -ve sign) by 20%.</span>
Answer:
A, 14
Step-by-step explanation:
Assuming that she has a total of d dollars, and spends half of it, then we have 1/2d. She then spends <em>another</em> 6 dollars, and therefore we would subtract. She is left with one dollar.
1/2d-6=1
Working backwards, we can solve for d, her total amount of money:
1/2d=7
d=14
<em>I hope this helps! :)</em>
The answer is v=5x^2-100x+500. First, since we are finding the volume of a square you already know that the equation for a square is volume= length*width*height. Because 5 inches was cut off from each side, that means that each side is now 10 inches shorter than it originally was. So, then you substitute the values into the formula. So the length is x-10 and the width is also x-10 and the height is 5in. Then you write the formula like this (x-10)(x-10)5. Second, you substitute the values into the formula. Since there are 2 x's that would make x^2 and add that to 5 that would make 5x^2. Then you multiply -10*10=-100. Finally, you multiply -10*-10-5=500. Then you add them all together to get 5x^2-100x+500
About 1920, just find the volume by multiplying length times width times height
and divide that by the 1-inch cubes. hope this helps