(1)原式=7.5×(10+0.4)
=75+3
=78 (2)原式= 4.36÷(0.25×40)
= 4.36÷10
=0.436
(3)原式=(3.3+1.77)×7.8
=5.07×7.8
=39.546 (4)原式=(0.1+0.9)×17-(0.79+0.21)
=17-1
=16
(1)原式=7.5×(10+0.4)
=75+3
=78 (2)原式= 4.36÷(0.25×40)
= 4.36÷10
=0.436
(3)原式=(3.3+1.77)×7.8
=5.07×7.8
=39.546 (4)原式=(0.1+0.9)×17-(0.79+0.21)
=17-1
=16