Problem

Solve the compound inequality. Express your answer using inequality signs, and then write your answer using interval notation.
9<7x+511

Answer

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Answer

Finally, we check our solution. We can do this by substituting a number from the interval into the original inequality. For example, if we choose x=0, we get 9<7(0)+511, which simplifies to 9<511. This is true, so our solution is correct.

Steps

Step 1 :First, we need to solve the compound inequality. We can do this by breaking it down into two separate inequalities: 9<7x+5 and 7x+511.

Step 2 :Let's start with the first inequality 9<7x+5. We can solve for x by first subtracting 5 from both sides of the inequality, which gives us 14<7x.

Step 3 :Next, we divide both sides of the inequality by 7 to isolate x. This gives us \(-2-2\).

Step 4 :Now, let's solve the second inequality 7x+511. We can solve for x by first subtracting 5 from both sides of the inequality, which gives us 7x6.

Step 5 :Next, we divide both sides of the inequality by 7 to isolate x. This gives us x67.

Step 6 :So, the solution to the compound inequality is x>2 and x67. In interval notation, this is (2,67].

Step 7 :Finally, we check our solution. We can do this by substituting a number from the interval into the original inequality. For example, if we choose x=0, we get 9<7(0)+511, which simplifies to 9<511. This is true, so our solution is correct.

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