14 = 31.7 - 3x
-17.7 = -3x <---- I subtracted 31.7 from both sides
5.9 = x <---- I divided both sides by -3
Answer: Ali would need to drive 350 miles for the two plans to cost the same.
Step-by-step explanation:
This question can be solved by creating two equations using the information supplied in the question and then solving these simultaneously.
Let the cost be C.
Let the number of miles be M.
Let the initial payment be i.
Let the rate per mile driven be R.
Plan 1:
C = i+R×M
C = 70+0.60M ... equation 1
Plan 2:
C = i+R×M
C = 0+0.80M
C = 0.80M ...equation 2
Substituting equation 2 into equation 1:
0.80M = 70+0.60M
0.80-0.60M = 70
0.20M = 70
M = 70/0.20
M = 350 miles
Plugging 10 for k in the expression gives us
We simplify this expression to
251 is your answer
To tessellate a surface using a regular polygon, the interior angle must be a sub-multiple (i.e. factor) of 360 degrees to cover completely the surface.
For a regular three-sided polygon, the interior angle is (180-360/3)=60 °
Since 6*60=360, so a regular three-sided polygon (equilateral triangle) tessellates.
For a regular four-sided polygon, the interior angle is (180-360/4)=90 °
Since 4*90=360, so a regular four-sided polygon (square) tessellates.
For a regular five-sided polygon, the interior angle is (180-360/5)=108 °
Since 360/108=3.33... (not an integer), so a regular five-sided polygon (pentagon) does NOT tessellate.
For a regular six-sided polygon, the interior angle is (180-360/6)=120 °
Since 3*120=360, so a regular six-sided polygon (hexagon) tessellates.
