(1)67.8÷12.5×0.8
=67.8÷(12.5×0.8)
=67.8÷10
=6.78( )
(2)0.8×1.25×4×0.25
=0.8×1.25+4×0.25
=1+1
=2( )
(3)4.4×0.25
=4×0.25×0.4
=1×0.4
=0.4( )
(4)6.4÷0.8+3.6÷0.2
=(6.4+3.6)÷(0.8+0.2)
=10÷1
=10( )
同类型试题
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2