Answer is a= 51/7 or 7 2/7
Step by step
-2/3 (a + 3) = 5/3a - 19
Distribute to resolve parentheses
-2/3a -2 = 5/3a - 19
Now to move variables to one side
Add 2/3a to both sides
-2/3a + 2/3a -2 = 5/3a + 2/3a -19
Combine like terms
-2 = 7/3a -19
Add 19 to both sides to isolate variable
-2 +19 = 7/3a -19 + 19
17 = 7/3a
Divide both sides by 7/3 to solve for a
(Remember when you divide a fraction, flip it and multiply.)
17 * 3/7 = a
51/7 = a
Picture attached shows steps in order, I think that is what you also needed?