It's 8! range is just the greatest value minus the lowest value
(=^_^=)
We need to start from the innermost parenthesis and work our way out.
The first parenthesis is 
. These are not like terms because one involves a variable, while the other is a constant term. Two terms are summable if they involve the same power(s) of the same variable(s).
So, we can take one step outwards, and we arrive to the square brackets. We have
and 2z and -13z are like terms, so we can sum them:
Finally we arrive to the whole expression, which is
Because, again, 5z and 11z were like terms.
X = 2 expand the brackets and then collect like terms (x's on one side) and then dived to get x on its own! :)
Answer:
Both rates and ratios are a comparison of two numbers. A rate is simply a specific type of ratio. The difference is that a rate is a comparison of two numbers with different units, whereas a ratio compares two numbers with the same unit. For example, in a room full of students, there are 10 boys and 5 girls. This means the ratio of boys to girls is 10:5.
