Two cars travel along a highway at the same speed. Car A travels 20 km in 12 min.
How long will it take Car B to travel 50 km?

30 mins

Step-by-step explanation:

speed = distance/ time

speed of car A

= 20/ 12 km/ min

= 5/ 3 km/ min

also, speed of car A = speed of car B

speed of car B = 5/ 3 km/ min = 50km / time taken (in mins)

=> t = 30 mins

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

the one below it is a function