2*4*8*0.5*0.125*0.25*(0.4321+0.5679)
Tính bằng cách thuận tiện nhất :
a / 2 x 4 x 8 x 0.5 x 0.125 x 0.25 x ( 0.4321 + 0.5679 )
b /3.7 x 3.8 + 8.3 x 3.7 - 0.4 x 3.7 x 5
a, 2 x 4 x 8 x 0,5 x 0,125 x 0,25 x ( 0,4321 + 0,5679 )
= ( 2 x 0,5 ) x ( 4 x 0,25 ) x ( 0,125 x 8 ) x ( 0,4321 + 0,5679 )
= 1 x 1 x 1 x ( 0,4321 + 0,5679 )
= 1 x ( 0,4321 + 0,5679 )
= 1 x 1 = 1
b, 3,7 x 3,8 + 8,3 x 3,7 - 0,4 x 3,7 x 5
= 3,7 x ( 3,8 + 8,3 ) - ( 0,4 x 5 ) x 3,7
= 3,7 x 12,1 - 2 x 3,7
= 3,7 x ( 12,1 - 2 )
= 3,7 x 10,1 = 37,37
1/2:0.5-1/4:0.25+1/8:0.125-1/10:0.1
1/2 : 0.5 - 1/4 : 0.25 + 1/8 : 0.125 - 1/10 : 0.1
1/2 : 0.5 - 1/4 : 0.25 + 1/8 : 0.125 - 1/10 : 0. 1
= 1 - 1 + 1 - 1
= 0 + 0
= 0
\(\frac{1}{2}:0,5-\frac{1}{4}:0,25+\frac{1}{8}:0,125-\frac{1}{10}:0,1\)
\(=\frac{1}{2}:\frac{1}{2}-\frac{1}{4}:\frac{1}{4}+\frac{1}{8}:\frac{1}{8}-\frac{1}{10}:\frac{1}{10}\)
\(=1-1+1-1=0\)
1/2:0.5-1/4:0.25+1/8:0.125-1/10:0.1
1/2:0.5-1/4:0.25+1/8:0.125-1/10:0.1
1/2:0,5-1/4:0,25+1/8:0,125-1/10:0,1
=1-1+1-1
=0
Tính bằng cách thuận tiện
1/10 + 1/2 : 0.5 - 1/4 : 0.25 + 1/8 : 0.125
\(\dfrac{1}{10}+\dfrac{1}{2}:0,5-\dfrac{1}{4}:0,25+\dfrac{1}{8}:0,125\)
\(=\dfrac{1}{10}+\dfrac{1}{2}\times2-\dfrac{1}{4}\times4+\dfrac{1}{8}\times8\)
\(=\dfrac{1}{10}+1-1+1\)
\(=\dfrac{1}{10}+1=\dfrac{1}{10}+\dfrac{10}{10}=\dfrac{11}{10}\)
\(\dfrac{1}{10}+\dfrac{1}{2}\div0,5-\dfrac{1}{4}\div0,25+\dfrac{1}{8}\div0,125\)
= 0,1 + 0,5 x 2 - 0,25 x 4 + 0,125 x 8
= 0,1 + 1 - 1 + 1
= 1,1 - 1 +1
= 0,1 + 1
= 1,1
`#3107.101107`
\(\dfrac{1}{10}+\dfrac{1}{2}\cdot0,5-\dfrac{1}{4}\div0,25+\dfrac{1}{8}\div0,125\)
\(=\dfrac{1}{10}+\left(\dfrac{1}{2}\div0,5\right)-\left[\left(\dfrac{1}{2}\right)^2\div\left(0,5\right)^2\right]+\left(\dfrac{1}{2}\right)^3\div\left(0,5\right)^3\)
\(=\dfrac{1}{10}+\left(\dfrac{1}{2}\div0,5\right)-\left(\dfrac{1}{2}\div0,5\right)^2+\left(\dfrac{1}{2}\div0,5\right)^3\)
\(=\dfrac{1}{10}+1-1^2+1^3\)
\(=\dfrac{1}{10}+1\)
\(=\dfrac{11}{10}\)
Tính nhanh:
\(25\%+\dfrac{3}{4}+\dfrac{1}{2}:0.5-\dfrac{1}{4}:0.25+\dfrac{1}{8}:0.125\)
`25%+3/4+1/2:0,5-1/4:0,15+1/8:0,125`
`=1/4+3/4+1/2xx2-1/4xx4+1/8xx8`
`(1/4+3/4)+(1/2xx2)-(1/4xx4)+(1/8xx8)`
`=1+1-1+1`
`=2`
tính nhanh
1/2:0.5-1/4|:0.25+1/8:0.125-1/10:0.1
tinh nhanh
1/2/0.5-1/4/0.25+1/8/0.125-1/10/0.1