David is rowing a boat upstream. the river is flowing at a speed of 2 miles per hour. david starts rowing at a speed of 6 miles per hour, but as he gets tired his speed decreases (at a rate of 1 mile per hour, every hour). which equation represents the speed of the boat for x hours spent rowing?
y = 6 − 2x
y = x − 4
y = 4 − x
y = 6 − x
y = x + 4

y = 4 - x

Step-by-step explanation:

Given,

The speed of David's boat = 6 miles per hour,

Speed of stream = 2 miles per hour,

So, the speed of boat in upstream = Speed of boat - Speed of stream

= 6 - 2

= 4 miles per hour,

Now, this speed is decreasing at the rate of 1 miles per hour,

So, the total decreased speed in x hours = x miles per hour,

Hence, the final speed of boat after x hours = ( 4 - x ) miles per hour,

If y represents the final speed ( miles per hour ) of boat after x hours ,

⇒ y = 4 - x

Which is the required equation.

"it's not the heat, it's the humidity".   that's a partly valid phrase you may have heard in the summer, but it's actually both.   the heat index, also known as the apparent temperature, is what the temperature feels like to the human body when relative humidity is combined with the air temperature.   this has important considerations for the human body's comfort.   when the body gets too hot, it begins to perspire or sweat to cool itself off.   if the perspiration is not able to evaporate, the body cannot regulate its temperature.   evaporation is a cooling process.   when perspiration is evaporated off the body, it effectively reduces the body's temperature.   when the atmospheric moisture content (i.e. relative humidity) is high, the rate of perspiration from the body decreases.   in other words, the human body feels warmer in humid conditions.   the opposite is true when the relative humidity decreases because the rate of perspiration increases.   the body actually feels cooler in arid conditions.   there is direct relationship between the air temperature and relative humidity and the heat index, meaning as the air temperature and relative humidity increase (decrease), the heat index increases (decreases).

step-by-step explanation:

y=x+9

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step-by-step explanation: