......................,.,................

a=6, b=2
Step-by-step explanation:
Use simplification into substitution
[tex]\frac{a}{3} =1+\frac{2}{b}[/tex]
[tex]a=3(1+\frac{2}{b})[/tex]
[tex]a=3+\frac{6}{b}[/tex]
We can now plug this value of a into the second equation.
[tex]\frac{3+\frac{6}{b} }{4} +\frac{3}{b} =3[/tex]
Get rid of fractions in the numerators and/or denominators
[tex]\frac{3b+6}{4b} +\frac{3}{b} =3[/tex]
Then we can match the denominators
[tex]\frac{3b+6}{4b} +\frac{12}{4b} =3[/tex]
Combine
[tex]\frac{3b+18}{4b} =3[/tex]
Divide both sides by three
[tex]\frac{b+6}{4b} =1[/tex]
Get rid of fractions
[tex]b+6=4b[/tex]
Single out b
[tex]6=3b[/tex]
[tex]b=2[/tex]
Now we can plug it into the equation
[tex]\frac{a}{3} -\frac{2}{2} =1[/tex]
[tex]\frac{a}{3} =2[/tex]
[tex]a=6[/tex]
Now we can check it;
[tex]\frac{6}{3} -\frac{2}{2} =1[/tex]
↑CORRECT
[tex]\frac{6}{4} +\frac{3}{2} =3[/tex]
↑CORRECT