Answer:
22 kids
Step-by-step explanation:
R (red shirts)
Y (yellow shirts)
R= Y+12 (to make them equal, you need to add 12 to the yellow because it tells you that there are 12 more red shirts than yellow)
R+Y=32 (the amount of students in the class)
Substitute R from the first equation into the second one.
(Y+12) + Y = 32
2Y +12 =32 (subtract 12 from both sides)
2Y =20 (divide by 2 on both sides)
Y=10
Now you know the amount of kids wearing yellow shirts.
Subtract the whole class and the yellow shirts.
32-10= 22