The x shows how they are meeting with the things to be with
Increase $110,000 by 20% 3 times.
110,000 x 0.2 = 22000
(0.2 is 20% as a decimal, we needed to convert it to multiply it)
So we must add 22000 to 110,000, then take 20% of the new cost, and repeat.
Add them
110,000 + 22000 = 132000
Take 20% of new value
132000 x 0.2 = 26400
Add that
132000 + 26400 = 158400
Take another 20% of that
31680
Add them
158400 + 31680 = 190080
So the value is now $190,080
A much more efficient way to do this would be multiplying 1.2 instead of 0.2, and skipping the adding part, as you already took 100% of it and are adding 20% more.
Hope this helps!
C.264.4 that should answer your question
Equation: (70 + 70*.05) + (580 + 580*.07) + (620 + 620*.10) = Total Spent
Solving for this gets you $1320.30.
Well maybe because the only thing that is different is the - and +
