Now I need help with math.

It looks easy for me to do but it’s confusing I can’t figure out what I have to do please help!!

The questions are in the picture. Number 1 and number 2 are already answered I just need to do 3, 4, 5, 6!

And if you can’t see the questions correctly they are under this text!!

[tex]3. [\frac{3}{4}x +\frac{3}{2} x=\frac{9}{4}]\\ \\ 4. [\frac{8}{3} r-\frac{9}{4} r=-\frac{5}{12}] \\ \\ 5. [r-\frac{10}{3} +\frac{1}{2} =-\frac{11}{6}]\\ \\ 6. [-\frac{5}{2} a+\frac{4}{3} +\frac{2}{3} =\frac{13}{4}]\\ \\[/tex]