McGraw Hill Glencoe Algebra 1, 2012
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McGraw Hill Glencoe Algebra 1, 2012 View details
3. Solving Multi-Step Inequalities
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Exercise 46 Page 302

Are the variable terms all gathered on one side of the inequality?

{z|z<- 2}

Practice makes perfect

Solving inequalities is done in the same way as solving equations, using inverse operations to isolate the variable. Just remember to reverse the inequality symbol when multiplying or dividing the inequality by a negative number.

Solving the Inequality

We will start solving by using the Subtraction Property of Inequality to combine all the z-terms on one side of the inequality. From there, we will use the Division Property of Inequality to eliminate the coefficient.
5.6z+1.5 < 2.5z - 4.7
3.1z+1.5 < - 4.7
3.1z < - 6.2
z < - 2

This tells us that all values less than - 2 satisfy the inequality. Knowing this, let's write the solution set. {z|z<-2}

Checking Our Solution

We can check our solution by substituting a few arbitrary values into the given inequality. The value satisfies the inequality if the inequality remains true after substituting and simplifying.

z 5.6z+1.5 < 2.5z - 4.7 Evaluate
- 3 5.6( - 3)+1.5 < 2.5( - 3) - 4.7 - 15.3 < - 12.2
- 2 5.6( - 2)+1.5 < 2.5( - 2) - 4.7 - 9.7 ≮ - 9.7
-1 5.6( -1)+1.5 < 2.5( -1) - 4.7 -4.1 ≮ -7.2

We can conclude that, as long as z is less than - 2, the inequality is satisfied. This means our solution is correct.