Exercise 41 Page 175

The above tells us that all values greater than or equal to -1 will satisfy the inequality. Below we demonstrate the inequality by graphing the solution set on a number line. Notice that d can equal -1, which we show with a closed circle on the number line.

Checking Our Solution

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

We can conclude that, as long as d is greater than or equal to - 1, the inequality is satisfied.