The 2 smallest lengths in a triangle have to add up to be greater that the longest side of the triangle. In this case, the longest side is 20. The 2 smallest sides are 5 and 10. 5+10=15, but 15<20. This is why these 3 lengths can’t create a triangle.
If 12 dozen were bought for $90 that means each CD was bought at the price of $0.66
If he sold all 60 of the CD's for 5 for $12, he'd make $144.
Subtract the income by the original buying price to find his profit. $144 - $90
The peddler made $54 profit.
True, u can choose any two distinct points on a line to calculate the slope