I think the answer is x = -4.
perimeter or rectangle= 2l+2w
Surface area of a cylinder=2(pi)r^2+2(pi)r
Volume of a triangular prism=Bh
Area of a circle=(pi)r^2
Answer: 10
<u>Step-by-step explanation:</u>
varies directly means: 
Step 1: solve for k ⇒ 
Step 2: plug in the given value and k to solve for the missing value: 
42(5) = 21(x)

2(5) = x
10 = x
Well, we know the amount of cups of sugar it calls per 1/2 teaspoon, so all we need to do to find the amount of cups of sugar per teaspoon is multiply by 2, since 1/2 teaspoon * 2 = 1 teaspoon.
2/3 * 2 = 1 1/3
The unit rate is 1 1/3 cups per teaspoon
Hope that helped =)
The emissions per capita measurement is a better because it shows the number of people divided by the emissions.
<h3>What is the difference between total emissions and emissions per capita?</h3>
The emissions per capita show the emissions per each citizen or inhabitant, while the total emissions show only the emissions of the country.
<h3>Which one is better?</h3>
The per capita gauge is better because whether a country is polluting more or not depends on how much each citizen pollutes. This information is useful to create laws that reduce pollution.
Learn more about pollution in: brainly.com/question/23857736
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