Posted by snow on .
A 5mile cab ride costs$7.20 a 9 mile cab ride costs $11.60 find a linear equation that models a relationship between cost c and distance d?
Answers are
C =1.44 d +4.40
C=1.10 c +4.40
C=1.29 d+1.70
C=1.10 d +1.70
Thanks

algebra 
Steve,
If the formula is c=ad+b, then
5a + b = 7.20
9a + b = 11.60
Solve for a and b.
Or, note that as the distance increased by 4, the cost increased by 4.40
So, the slope is 1.1
That eliminates two of the choices right away. Now just see how much extra there is in each case when multiplying the distance by 1.1 
algebra 
snow,
Would the answers be c=1.10c+4.40

algebra 
Steve,
ummm. No
1.1(5) = 5.5
5.5+1.7 = 7.2
c = 1.1d + 1.7
Did you even try your formula against the data?