Big Ideas Math: Modeling Real Life, Grade 6
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8. Solving Inequalities
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Exercise 49 Page 398

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

Solution: b ≤ 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.
2 25b-1 310b ≤ 6 35
2* 5+2/5b-1*10+3/10b ≤ 6*5+3/5
Simplify left-hand side
12/5b - 13/10b ≤ 33/5
12* 2/5* 2b - 13/10b ≤ 33/5
24/10b-13/10b ≤ 33/5
24-13/10b ≤ 33/5
11/10b ≤ 33/5
Next, we will use the Multiplication Property of Inequality to simplify the inequality even further.
11/10b ≤ 33/5
10 * 11/10b ≤ 10 * 33/5
11b ≤ 10* 33/5
11b ≤ 10* 33/5
11b ≤ 330/5
11b≤ 66
Finally, let's use the Division Property of Inequality to simplify the inequality.
11b≤ 66
11b/11 ≤ 66/11
Calculate quotient
11/11b≤ 66/11
1b≤ 66/11
b≤ 66/11
b ≤ 6
Note that all values of b less than or equal to 6 satisfy the inequality. Now let’s graph the inequality on a number line. Since b is all values less than or equal to 6, we will shade to the left of our point at 6, including 6 with the closed circle.