<h3>
Answer: D. regular hexagon</h3>
A hexagon is composed of 6 congruent equilateral triangles. Each equilateral triangle has interior angle of 60 degrees. Adding 6 such angles together gets you to 360 degrees. So we've done one full rotation and covered every bit of the plane surrounding a given point. Extend this out and you'll be able to cover the plane. A similar situation happens with rectangles as well (think of a grid, or think of tiles on the wall or floor)
In contrast, a regular pentagon has interior angle 108 degrees. This is not a factor of 360, so there is no way to place regular pentagons to have them line up and not be a gap or overlap. This is why regular pentagons do not tessellate the plane. The same can be aside about decagons and octagons as well.
X/x+9 (original fraction)
x+1/ x+10 = 4/13
x+1=4 so x=3 and x+10=13 so again x=3
now that you have the value of x, substitute it into the original fraction to get:
3/12
What you would do is take the denominators and multiply them by each other, then multiply the numerators by that same number. So like 4/10 and 4/9. You would say, (denominators) 10x9=90 and (numerators) 4x9=36. So your first fraction would be 36/90. Next, you would take (denominators) 9x10=90 and (numerators) 4x10=40. So your second fraction would become 40/90. Now it's a lot easier to compare. 36/90 < 40/90 would be the answer to my problem. I hope I helped!
They are running 13.1 miles per hour since half of 26.2 is 13.1