Maria and kim left town at 9: 00 am and traveled the same route in separate cars. kim drove 3 h at a steady speed, then slowed down 15km/h for 3 more hours. maria averaged 5 km/h more than kim's original speed for the entire trip and arrived at their destination at 2 pm. what was kim's original speed?

70 km/h

Step-by-step explanation:

Let the original speed of Kim = x km/h

Kim drove with this speed for 3 hours.

Total distance covered by Kim during this period is 3 * x km

After 3 hours , Kim slowed down by 15 km/h.

So, new speed of Kim is (x-15) km/h

Kim drove at this speed for another 3 hours .

Distance covered by Kim during this period = 3 * (x-15) km

So, total distance covered by Kim is \[3x + (3x-45)\] km

This is equivalent to \[6x - 45\] km

Maria's speed = (x+5) km/h

Maria started at 9 am and reached the destination at 2 pm. So she drove for 5 hours.

Total distance covered by Maria is \[5 * (x+5)\] km

This is equivalent to \[5x + 25\] km

As per the given data, 6x - 45 = 5x + 25

=> 6x - 5x = 45 + 25

=> x = 70

So Kim's original speed was 70 km/h

answer: expected value of x = 1.0

step-by-step explanation:

p(x=0) = 0.25

p(x=1) = 0.50

p(x=2) = 0.25

expected value for x = 0×0.25 + 1×0.5 + 2×0.25 = 1.0

since your problem is x^4 = 81, what you have to undeo is the "to the fourth power" part.

the inverse (opposite operation) of "to the fourth power" is "to the fourth root".

  (x^4) ^ ¼   = 81 ^ ¼  

  81 = 3^4     so (3 ^ 4) ^ ¼   =   3 ^ 1   = 3

by hand: (3 ^ 4) ^ ¼   =   3 ^ (4 x ¼) = 3 ^ 1   = 3   (when you take a power to a power, multiply the exponents.)

or, do it by calculator. one way of finding the fourth root is to use ^ (1/4)

step-by-step explanation: