The balance in my bank account went down $85 in 15 days. How much did it change per day. Use a positive number to represent a gain of money and a negative number to represent a loss of money.
The change in balance is a loss of money, so the change is -85.
The change of -85 occurred in 15 days, so the average change per day is
For every 33 green triangles, we have 77 yellow triangles. So using the original ratio 33:77 we can simplify this by dividing both sides by 11 so that we get the ratio 3:7 so for every 3 green triangles we have 7 yellow triangles.