Can you be more specific?
First you create a proportion (30/100=x/120). After you solve this, next you subtract this answer from 120. Then create a proportion for 40% (40/100=x/120). Then add this number to the first answer you got when you subtracted the answer from your first proportion from 120.
Answer:
1386
Step-by-step explanation:
If you have trouble with that, you can multiply 66 by 20, then 66*1, and add them (break apart the 21.)
The equation x = 180 - (31 + 40) can be used. Because the angles are in a straight line ad straight line equals 180 degrees
