Step-by-step explanation:
1.(12×2+1)/2 - (4×9+1)/4 = 3¼.
2.(5×4+3)/4 - (12×2+5)/12 = 3⅓.
3.(5×7+1)/5 - (10×3+7)/10 = 3½.
4.(3×11+2)/3 - (2×8+1)/2 = 3⅙.