Answer:
You got them both right, no other choices need to be selected.
Explanation:
Both the choices you have put yes to, will give an answer equal to 32.
Since they want us to find the full amount of students in his class, and 20 is 4 more than half the class 20-4=16 and then 16 x 2 is 32
1/2m+4=20 is correct because, if you move the 4 across the equal sign it become a negative and will be subtracted from the 20 therefore becoming 16. 1/2m=16. Now left with only the 1/2m we must multiply by 2 because 1/2 is a fraction and mutipliting it by 2 will allow us to get 1/2 to equal 1 and m by itself.
1/2m*2=1m
1m=16*2 Keep in mind you must do the same to both sides so the 16 is multiplied as well.
4th option: Same thing different order
Just send 1/2m over equal sign and 4 over the equal sign to trade places. and you will have 1/2m=16