1. Solving Inequalities by Addition and Subtraction
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To algebraically express a verbal inequality, we will need to translate the given information into mathematical symbols and operations.
is more thancan be expressed as >. This symbol will be at the center of our expression. ... >... We will translate any verbal expression that comes before
is more thanon the left-hand side of the inequality symbol. If we let n represent
a number,we can form this expression.
twice a number
2 n
On the right-hand side of the inequality symbol we will translate any verbal expression that comes after is more than.
the sum of that number and 9
n + 9
Finally, we can bring these two expressions together to form the inequality.
2n>n+9
We can check our solution by substituting a few arbitrary values into the inequality translated above. The value satisfies the inequality if the inequality remains true after substituting and simplifying.
n | 2n>n+9 | Simplify |
---|---|---|
8 | 2( 8)? > 8+9 | 16≯ 17 |
9 | 2( 9)? > 9+9 | 18≯ 18 |
10 | 2( 10)? > 10+9 | 20>19 |
We can conclude that as long as n is greater than 9, the inequality is satisfied.