Tinh bang cach hop li : luy~thua` so^
A,7.8.39+56.30+14.4.31
B,175+35-275+100
C,350:7+140:7+7:7
D,25.17+23.32
bai1:tinh nham bang cach hop li :
a,7.8.39+56.30+14.4.31
b,175+35-275+100
c,350.7+140.7+7:7
a) 7.8.39+56.30+14.4.31
= 56.39+56.30+56.31
= 56.(39+30+31)
= 56.100
=5600
b) 175+35-275+100
= (175-275)+100+35
= -100+100+35
= 0+35
=35
c) 350.7+140.7+7:7
= 7.(350+140)+1
= 7.490+1
= 3430+1
=3431
a, 7.8.39+56.30+14.4.31
=56.39+56.30+56.31
=56.(39+30+31)
=56.100
=5600
b, 175+35-275+100
=(175+100-275)+35
=(375-375)+35
=0+35
=35
c, 350.7+140.7+7:7
=7.(350+140)+7:7
=7.490+1
=3430+1
=3431
dinh nghia luy thua bac n cua a
neu cach viet mot tap hop . ap dung viet tap hop A cac so tu nhien x ma x thuoc so tu nhien khac khong va x nho hon hoac bang 7
khi nao so tu nhien a chia het cho so tu nhien b
luy thua bac n la h cua n thua so a
co 2 cach:+liet ke ca phan tu
+chi ra tinh chat dac trung
A={1;2;3;4;5;6;7}
a chia het cho b khi a la boi cua b va b la uoc cua a
nho k cho mk nha
Cach 1 : Tinh so bi chia, tinh so chia roi tinh thuong.
Cach 2:Chia hai luy thu cun co so roi tinh ket qua
a) 210:28 b) 46 : 43
c) 85 : 84 d) 74: 74
54*275+825*15+275 tinh bang cach thuan hop li
=54.275+275+825.15
=275.55+825.15
=275.55+55.15.15
=55.(275+225)
=55.500
=27500
tinh bang cach hop li
1/7 + 2/7 + 3/7 + ................. + 3 5/7 + 3 6/7
Ta có: \(\frac{1}{7}+\frac{2}{7}+\frac{3}{7}+...+\frac{35}{7}+\frac{36}{7}=\frac{1+2+3+....+36}{7}\)
\(=\frac{\left(1+36\right)\times36\div2}{7}=\frac{666}{7}=95\frac{1}{7}\)
Vậy giá trị của biểu thức là \(95\frac{1}{7}\)
1/7 + 2/7 + 3/7 + ............... + 35/7 + 36/7 = 666/7
tinh bang cach hop li
a, 3/7+2/9+5/9+-9/10
b, 3/4+-1/7+14/7+-6/7+32/28
Tinh bang cach hop li A= [1-(1/49)-1/49-1/(7*7)*(7*7)/4-4/7-2/7*2/7-2/243
Tinh bang cach hop li
7/13×5/14×39/15
=( 7*5*39)/(13*14*15)
=(7*5*3*13)/(13*7*2*5*3)
=1/2
\(\frac{7}{13}x\frac{5}{14}x\frac{39}{15}\)
\(=\frac{7x5x39}{13x14x15}\)
\(=\frac{7x5x13x3}{13x7x2x5x3}\)
\(=\frac{1}{2}\)
Bai3:Tinh bang hai cach
Cach 1:Tinh gia tri so bi chia,so chia roi tinh gia tri ket qua.
Cach2:Chia hai luy thua cung co so.
a,3 mu 6 :3 mu 4
b,5 mu 7: 5 mu 5
c,3 mu 9: 3 mu 3
d,5 mu 5: 5
e,3 mu 2: 3 mu 0