The answer set is {5,7,9,11}
The range is 30. To find the range, you subtract the largest number, which is 100, by the smallest number, which is 70.
The formula to solve for the area of a cube is
A=6a^2
you plug your edge in for the a
A=6(2)^2
A=6(4)
A=24 inches
your surface are would be 24 inches
Okay. In my opinion, all the class has to do is simplify the expressions and compare. But they want to substitute instead.
Well then.
First, let's notice that these are linear expressions, meaning that if they are equivalent then all their values match up.
Number 1 is not a good one. Just because they're both positive doesn't mean anything; they have to be <em>the same.</em>
This also eliminates 3.
Number 2 is a good one, but it's not as reliable. If, for instance, the two expressions are <em>not </em>equivalent and you get lucky enough to pick that one value they intersect at (or have in common), then you'd be wrong when you say they are equivalent.
Number 4 makes the most sense because if both expressions are equivalent, then every value matches up. If not, then only one will. So having two values to substitute will most definitely answer the class question.
Hope this helps, let me know if I messed up! ;)
