Respuesta :
The equation which can be used to find c is (D) 4(9 - c) = 2(9 + c).
What is an equation?
- An equation is a formula in mathematics that expresses the equality of two expressions by connecting them with the equals sign =.
- A mathematical statement made up of two expressions joined by an equal sign is known as an equation.
- 3x - 5 = 16 is an example of an equation.
- We get the value of the variable x as x = 7 after solving this equation.
To find the equation which can be used to find c:
- Since Distance = Speed × Time.
- Here c represents the speed of the current.
- Thus, if the boat has a speed of 9 mph in still water.
- Then its speed upstream = ( 9 - c ) mph.
- Also, It takes the boat 4 hours to travel upstream.
- Hence, total distance in upstream = 4 ( 9 - c ).
- Similarly its speed in downstream = ( 9 + c ) mph.
- Also, It takes the boat 2 hours to travel downstream.
- Hence, total distance in downstream = 2 ( 9 + c ).
- Since the distance upstream and downstream is equal.
- ⇒ 4 ( 9 - c ) = 2 ( 9 + c )
Therefore, the equation which can be used to find c is (D) 4(9-c)=2(9+c).
Know more about equations here:
https://brainly.com/question/2972832
#SPJ4
The correct question is given below:
A boat has a speed of 9 miles per hour in calm water. it takes the boat 4 hours to travel upstream but only 2 hours to travel the same distance downstream. which equation can be used to find c, the speed of the current in miles per hour?
(A) 2(9 - c) = 4(9 + c)
(B) 9 + c = 4(9 - c)
(C) 9 - c = 2(9 + c)
(D) 4(9 - c) = 2(9 + c)
