Apack of gum costs 75 cents. that is 3 cents less then three times what the pack cost 20 years ago. which equation could be used to find the cost of the gum 20 years ago

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If the gum costs 75 cents today, which is 3 cents less than three times what the pack cost 20 years ago, we just need to arrange what we know into an equation.

We know that the price of gum today is 75 cents, so we can leave that on one side of the equation as a constant. Also, since we are dealing only with cents and not dollars, there is no need to shift the decimal point to the left.

? = 75

Now, we can work the equation.

The problem tells us that 75 is 3 cents less than three times the old cost. So, if x is the old cost, we can work out the equation based on that.

It says that it's 3 cents less than 3 times x. The question is basically the equation in word form.

3x - 3 = 75

'3x' being the "three times the old cost" part, '- 3' being the "3 cents less" part, and '75' of course being the current price of a pack of gum.

Option C is your correct answer.

BTW if we were to solve this, we would see that the old price of a pack of gum is:

3x - 3 = 75

  + 3      + 3

3x = 78

/3      /3

x = 26

20 years ago, a 75-cent pack of gum cost 26 cents.

3x-3=20

Step-by-step explanation:

3x is the amount it is cost 20 years ago while -3 represents less than 3 cents and the 20 represents 20 years ago.

"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:

e^-kt = n/n0 = 0.79  

-kt = ln 0.79  

t = - ln 0.79/0.0001  

= 2357 years

step-by-step explanation: