Please help me?!! a motorboat takes 5 hours to travel 150 Miles going Upstream. the return trip takes 3 hours going Downstream .what is the rate of the boat in still water and what is the rate of the current ?

The the rate of the motorboat in still water is 40 km/h;  the rate of the current is  10 km/h.

Step-by-step explanation:

Let  u  be the rate of the motorboat in still water (in kilometers per hour),

let  v  be the rate of the current.

Then the rate of the motorboat going downstream is  u+v  km/h,

while its rate going upstream is  u-v  km/h.

From the other side, the rate of the motorboat going downstream is  150/3=50km/h = 30 km/h.

Thus you have these two equations

   u + v = 50    (1)   (for the rate downstream),   and

   u - v = 30    (2)   (for the rate upstream).

To solve the system, add equations (1) and (2). You will get

   2u = 50 + 30 = 80;   hence,

    u           = 80/2 = 40 km/h.

Then from the equation (1),  v = 50 - u = 50 - 40 = 10 km/h.

ANSWER.  The the rate of the motorboat in still water is 40 km/h;  the rate of the current is  10 km/h.

20%

step-by-step explanation:

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places