Big Ideas Math: Modeling Real Life, Grade 6
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Big Ideas Math: Modeling Real Life, Grade 6 View details
8. Solving Inequalities
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Exercise 9 Page 394

What can you do to isolate a variable in an inequality?

Solution: t < 6
Graph:

Practice makes perfect
Inequalities can be solved in the same way as equations, by performing inverse operations on both sides until the variable is isolated. The only difference is that when we divide or multiply by a negative number, we must reverse the inequality sign.
5 > 5t/6
5 * 6> 5t/6* 6
30 > 5t/6* 6
30 > 5t
30/5 > 5t/5
5t/5 < 30/5
Calculate quotient
5/5t < 30/5
1t < 30/5
t < 30/5
t < 6
We found that all values of t less than 6 will satisfy the inequality. Now let’s graph the inequality on a number line. Since t cannot equal 6, we draw an open circle at this point. Since t is all values less than 6, we will shade the part of the number line that represents numbers less than 6. This means that we shade to the left of our point at 6.