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24 votes
24 votes
Can you please explain how to get this answer solve the compound inequality 3x-4>5 or 1 -2x>=7

User Logancautrell
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1 Answer

19 votes
19 votes

(-\infty,3)\text{ }\cup\text{ }\lbrack3,\infty)

Step-by-step explanation

Step 1

solve the inequality 1


\begin{gathered} 3x-4>5 \\ \text{add 4 in both sides} \\ 3x-4+4>5+4 \\ 3x>9 \\ \text{divide both sides by 3} \\ (3x)/(3)>(9)/(3) \\ x>3 \end{gathered}

so, the solution of inequality 1 is


x>3

Step 2

solve inequality 2


\begin{gathered} 1-2x\ge7 \\ \text{subtract 1 in both sides} \\ 1-2x-1\ge7-1 \\ -2x\ge6 \\ \text{divide both sides by -2( remember swap the sign when multiplying or dividing by a negative number)} \\ \end{gathered}
\begin{gathered} -2x\ge6 \\ (-2x)/(-2)\leq(6)/(-2) \\ x\leq-3 \end{gathered}

Step 3

finally, we have or, it means the solution is the union of the sets,

hence

solution


\begin{gathered} x>3\text{ }\cup x\leq-3 \\ (-\infty,3)\text{ }\cup\text{ }\lbrack3,\infty) \end{gathered}

x

User Btown
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