There are many dentists in the world and it wold be hard to count the amount of dentists that use the toothpaste. Also, there are many brands of toothpaste and it would would be doubtful that “80%” of dentists would use the same one.
Answer:
k=13
Step-by-step explanation:
3k+6+4k-7+90=180
7k+89=180
k=180-89/7
k=13
Answer: 2
Step-by-step explanation:

To find the surface area, you need to do the following:
A side of the figure is a trapezoid, so you should do 13+5x7 (since there are 2 of the same sides there is no need to divide by two.) and it should equal 126. To find the area of the top of the figure, you need to do 5x2 which equals 10. The area of the bottom of the figure is 26 (13x2), then do 2x3x2 to get the sides on the left and right of the figure. After all of this, add them together. (126+10+26+12=174.)
The surface area should be 174mm.