Answer:
<em><u>1</u></em><em><u>.</u></em><em><u> </u></em><em><u>A cross section is the new face you see when you slice through a three-dimensional figure. For example, if you slice a rectangular pyramid parallel to the base, you get a smaller rectangle as the cross section.</u></em>
<u>Formula</u>
<em>An expression that uses variables to state a rule is a </em><u><em>formula</em></u>
<h2>
Explanation:</h2>
An expression that uses variables to state a rule is a formula. It's important to know that formulas uses the equals sign (=) and includes two or more variables. Formulas gives us information that we express symbolically. For example, the well known formula for the volume of a sphere is defined as:

So in this formula we have a relationship between the volume of a sphere and its radius, so if we have information about the radius of it we can easily calculate the volume of it.
<h2>Learn more:</h2>
Volume of prism: brainly.com/question/12501166
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Answer:
The answer is 1
Step-by-step explanation:
-50+50=1