embarrassed
contestada

4) Ori drove 203.75 miles while on vacation. Assuming he only drove at the set speeds 55 miles per hour
and 40 miles per hour, how long did he travel at each speed if he drove for 4.25 hours? (Hint: Make a
table.)
Answer: Ori drove 2.25 hours at 55 mph and 2 hours at 40 mph

I have to find out the best way to get to that answer, and I'm a bit stuck on how to get it.

Respuesta :

x=number of hours, when Ori drove  at 55 mph
y=number of hours, when Ori drove at 40 mph
We can suggest the next system of equations:

x+y=4.25
55x+40y=203.75

We solve this system of equation by substitution method.

x+y=4.25          ⇒y=(4.25-x)

55x+40(4.25-x)=203.75
55x+170-40x=203.75
15x=203.75-170
15x=33.75
x=33.75/15=2.25

y=(4.25-x)=4.25-2.25=2

Answer: Ori drove 2.25 hours at 55 mph and 2hours at 40 mph.

Otras preguntas