2.3×1.5+4.5÷0.75 (7.5+2.5)÷0.25
42-22=(4+2)×(4-2)=12
72-32=(7+3)×(7-3)=4092-42=(9+4)×(9-4)=65
152-52=(+)×(-)
x
3
☆
y
4
24