we are given the following inequations:
[tex]\begin{gathered} 34<3x+7,\text{ and} \\ 43>3x+7 \end{gathered}[/tex]Since both inequalities contain the term "3x + 7" we can use a single inequality of the following form:
[tex]34<3x+7<43[/tex]We notice that the direction of the inequality with respect to "3x + 7" remains the same. Now, to solve for "x" we will subtract 7 from the three sides of the inequality:
[tex]34-7<3x+7-7<43-7[/tex]Solving the operations we get:
[tex]27<3x<36[/tex]Now we divide the three sides by 3:
[tex]\frac{27}{3}<\frac{3x}{3}<\frac{36}{3}[/tex]Solving the operations:
[tex]9Thus we get the interval of solution for "x". In interval notation this is written as: [tex](9,12)[/tex]We use parenthesis because the inequality does not present an equal sign.