Tính hợp lí :
12/50 + 8% + 59/100 + 9%
Tính nhanh:
12/50 + 8% + 59/100 + 9%
= (12/50+8%) + (59/100+9%)
= 8/25+17/25
= 25/25
= 1
8% đổi thành 2/25, 9% đổi thành 9/100 có mẫu chung là 100
\(24/100+8/100+59/100+9/100=100/100=1\)
\(\dfrac{12}{50}+8\%+\dfrac{59}{100}+9\%\)
\(=\dfrac{24}{100}+\dfrac{8}{100}+\dfrac{59}{100}+\dfrac{9}{100}\)
\(=\dfrac{24+8+59+9}{100}=\dfrac{100}{100}=1\)
12/50 + 8% + 59/100 + 9%
\(\frac{12}{50}\)+ 8% + \(\frac{59}{100}\) + 9% +
= \(\frac{24}{100}\)+ \(\frac{8}{100}\)+ \(\frac{59}{100}\)+ \(\frac{9}{100}\)
= \(\frac{14+8+59+9}{100}\)
= \(\frac{100}{100}\)
= 1
Chúc bạn học tốt,k cho mik nha!
Tính nhanh
a) ( 1 + 1/2) x ( 1 + 1/3) x ( 1 + 1/4) x ……. X ( 1 + 1/2000)
b) 101 x 34 + 10,1 x 130 – 1,01 x 2700
c) 12/50 + 8% + 59/100 + 9%
a: \(=\dfrac{3}{2}\cdot\dfrac{4}{3}\cdot...\cdot\dfrac{2001}{2000}=\dfrac{2001}{2}\)
b: \(=101\left(34+13-27\right)=101\cdot20=2020\)
c: \(=24\%+8\%+59\%+9\%=1\)
Tính hợp lí
D=1-2-3-4+5-6-7-8+9-10-11-12+...+97-98-99-100
Tính hợp lí:
D = 1-2-3-4+5-6-7-8+9-10-11-12+...+97-98-99-100
D = 1-2-3-4+5-6-7-8+9-10-11-12+...+97-98-99-100
D = (1-2-3-4)+(5-6-7-8)+(9-10-11-12)+...+(97-98-99-100)
D = -8 + -8 +....+-8 ( Có 25 chữ số -8 )
D = -200
12/50+8%+59/100+0,09
=\(\frac{24}{100}+\frac{8}{100}+\frac{59}{100}+\frac{9}{100}\)
=1
\(\frac{12}{50}+8\%+\frac{59}{100}+0,09\)
\(=\frac{24}{100}+\frac{8}{100}+\frac{59}{100}+\frac{9}{100}\)
\(=\frac{24+8+59+9}{100}\)
\(=\frac{100}{100}\)
\(=1\)
_Chúc bạn học tốt_
a) ( 1 + 1/2) x ( 1 + 1/3) x ( 1 + 1/4) x ……. X ( 1 + 1/2000 )
b) 101 x 34 + 10,1 x 130 – 1,01 x 2700
c) 12/50 + 8% + 59/100 + 9%
a: \(=\dfrac{3}{2}\cdot\dfrac{4}{3}\cdot...\cdot\dfrac{2001}{2000}=\dfrac{2001}{2}\)
b: \(=10.1\left(340+120-270\right)=10.1\cdot190=101\cdot19=1919\)
c: \(=24\%+8\%+59\%+9\%=1\)
Tính bằng cách hợp lí
159.(18-59)-59.(8-73)
159.(18-59)-59.(8-73)=159.(-41)-59.(-65)
=(100+59).(-41)-59.(-65)
=100.(-41)+59.(-41)-59.(-65)
=(-4100)+59.[(-41)-(-65)]
=(-4100)+1416
=-2684
3/ Tính hợp lí :
a/ (- 25).(- 125).(- 4). (- 8)
b/ (- 50).(- 80).(- 2).(- 9)
\(a/ (- 25).(- 125).(- 4). (- 8)=[(-25).(-4)].[(-125).(-8)] =100.1000=100000\)
a/(−25).(−125).(−4).(−8)
= [(−25).(−4)].[(−125).(−8)]
= 100.1000
=100000
b/ (-50) . (-80) . (-2) . (-9)
= [(-50) . (-20)] . [ (-80) . (-9) ]
= 100 . 720
= 72000