Answer:
Step-by-step explanation:
Given the height of <em>6 </em>DVD cases, you can know the height of a <em>single</em> DVD case, by dividing the total height, in the number of cases ( for this problem).
Now, knowing the height of a <em>single</em> DVD case (), you can think the expression in this way: <em>If I already know the height of a single case, the height of any number of cases will be the result of multiplying the height of the case by the number of cases I want to stack.</em>
As the problem states, x is the number of cases in the stack, so, multiply the height of a single case for the number of cases (x).
This will result in the expression:
To know the height of a stack of 13 cases, just replace x=13 in the equation you just figured: , but don't forget the unit is mm, so the final result is <u>247 </u><u><em>mm.</em></u>