5x+2=12 find the value of x

How is this equation completed? i cannot find any examples in the book.

Which lines are parallel? justify your answer. lines p and q are parallel because same side interior angles are congruent. lines p and q are parallel because alternate exterior angles are congruent lines l and m are parallel because same side interior angles are supplementary lines l and m are parallel because alternate interior angles are supplementary.

If the numbers below were ordered from least to greatest, which number could you use to replace the blank? 0.20,2/5 □ , 3/4,8/10