9a-4+3(a-11)=23
9a-4+ 3a-33=23 (thats the distributive property)
-subtract 3a from both sides
-you get 6a-4-33=23
-add 33 to both sides of the equation
-you should get 6a-4=-10
-add 4 to both sides of the equation
- you should get 6a=-6
-then divide 6 on both sides of the equation so...