
Divide both the numerator and denominator by 9 to get;

Convert the improper fraction to a mixed number;
4 4/5. Check the linked photo for some explanation.
The difference of 7 and 7/8 and 3 1/4 can be restated as the difference between 63/8 and 13/4. This is just a change from mixed numbers to improper fractions.
We must now get a common denominator (the bottom part of a fraction). To get 8, we must multiply by 2 to the denominator of 13/4. Since we want this number to stay in the same value, we have to multiply the numerator by 2 as well (top part of the fraction). Therefore, we are getting the difference of 63/8 and 26/8. Doing this, we get (63-26)/8, so the answer is 37/8 = 4 5/8
18x^2 + 2x + y^2 = 1
<span>==> 18(x^2 + x/9) + y^2 = 1 </span>
<span>==> 18(x^2 + x/9 + 1/324) + y^2 = 1 + 1/18 </span>
<span>==> 18(x + 1/18)^2 + y^2 = 19/18 </span>
<span>==> (x + 1/18)^2/19 + (y - 0)^2/(19/18) = 1. </span>
<span>By comparing this to the standard form of an ellipse, the center is at (-1/18, 0). </span>
The solution is (8,8) which means that at 8 miles both cabs will cost $8