Answer: if under 15 miles, then use Red cab company. if over 15 miles, then use Yellow cab company
Step-by-step explanation:
first, need to identify equations for the each cab company.
let X be the mile driven and Y be the fare cost
red cab cost: Y= 1.25X + 3.50
yellow cab cost: Y = 1.15X + 5
I like to use the combination method to eliminate one variable
multiply -1 to one of the equation so -1[ Y= 1.25X + 3.50 ] = -Y = -1.25X -3.50
combine (add) them and eliminate the Y value
-Y = -1.25X - 3.50
Y = 1.15X + 5
-------------------------
0 = -0.1X + 1.5
0.1X = 1.5
X = 1.5/0.1 = 15
input X = 15 to the original equation(s) to find Y
Y = 1.15(15) + 5 = 17.25 +5 = 22.25
Y= 1.25(15) + 3.50 = 18.75 + 3.5 = 22.25
X = 15 miles and Y = $ 22.25
these values represents the red and yellow cab companies will charge the same amount when going exact 15 miles.
What if X is under or over 15 miles?
if X = 10 (under 15 miles)
red cab cost: Y= 1.2(10) + 3.50 = 12 + 3.50 = 15.50 (cheaper)
yellow cab cost: Y = 1.15(10) + 5 = 11.50 + 5 = 16.50
You can test out the X when greater than 15 miles
Conclusion.
if under 15 miles, then use Red cab company. if over 15 miles, then use Yellow cab company