How do you calculate percent of change( i forgot lol)

To calculate a change in something, you subtract. Example: going from 7 to 3 is a drop of 4 since 7-3 = 4. So we say "change of 4".

The percent change of going from 7 to 3 is a drop of 4/7 = 0.5714 = 57.14% approximately. If you had 7 dollars, and you lost 57.14% of those 7 dollars, then you'd have 3 dollars roughly.

Note how taking 57.14% of 7 yields us: 0.5714*7 = 3.9998 and which is fairly close to the result of 4 we got earlier.

So what I did with that example was

step 1) subtract the two values: 7-3 = 4

step 2) divide the result of step 1 over the starting value 7 to get 4/7 = 57.14%

In general, the formula is

where,

A = starting value

B = final value

C = percent change

If the value of C is positive, then you have a percent increase. If C is negative, then you have a percent decrease.

Put another way: if A > B, then theres a percent decrease. If A < B, then we have a percent increase.

The "100" tacked on at the end is to convert from decimal form to percent form. Eg: 0.37 converts to 37% after multiplying by 100

it has to have an angle of 90 degrees

using pemdas, (order of operations) you'll see the answer is 24.