Percent of change markup discount

You calculate the markup or markdown in absolute terms (you find by how much the quantity changed), and then you calculate the percent change relative to the original value. So they're really just another form of "increase - decrease" exercises.

Example:

A computer software retailer used a markup rate of 40%. Find the selling price of a computer game that cost the retailer $25.
The markup is 40% of the $25 cost, so the markup is:

(0.40)(25) = 10
Then the selling price, being the cost plus markup, is:

25 + 10 = 35

The item sold for $35.

Multiplication property of zero

Okay so for every triangle has three angles that always add up to 180 degrees. and to tell the difference between whether they are secure, right or obtuse is that acute: has one angle that is less than 90 degrees. right triangle means there is at least one angle that is exactly 90 degrees. and an obtuse angle has an angle that is bigger than 180 degrees. i’ll do #13 as an example: 13. 40 and 50 so if every triangle has 180 degrees 40+50= 90 degrees then180-90= 90 degrees so the third angle is 90 degrees and because this triangle has a 90 degree angle it means it is a right triangle