Answer:
-3a-12
Step-by-step explanation:
3(-2a-4)+3a
-6a-12+3a
-6a+3a-12
-3a-12
The answer for the question is 36 , 36
It makes the addition easier if you combine like terms like the two 1/2s and then make them all have the denominator of 12 (changing the numerators to equal it out)
Correct answer is: actual wingspan of airplane is 6 inches.
Solution:-
We are given that wingspan is 'a' feet and tail span is 'b' feet in a scale drawing.
And we are also given that tail span is 2 inches that is b=2 inches and 
Let us plugin the b value in above equation.

Multiplying with 2 on both sides.
a=3X2=6 inches.
Hence actual wingspan of airplane is 6 inches.