4x7=7x...
5x8=4x...
25dam=..kg
Tính (4x7+2)(6x6+2)(8x11+2)(100x103+2)/(5x8+2)(7x10+2)(9x12+2)...(99x102+2)
câu nào đúng câu nào sai
A 25dam + 17dam = 420m
B 4m5cm > 450 cm
C 999g + 1 kg = 1000 kg
D 12dm 5cm = 125 cm
Mn ơi giúp mik với mik đang rất vội !!
Câu đúng: D
Câu sai: B
Tick nha!! Tks
HT
a. 1 + 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256
b. 3/1x4 + 3/2x5 + 3/3x6 + 3/4x7 + 1/5x8
c. 2/1x3 + 2/3x5 + 2/5x7 + ............... + 2/2001x2003 + 2/2003x2005
Các bn vui lòng giải lời giải nha
a=511/256
b=647/20
c=mình đang suy nghĩ,nhưng nếu bạn k cho mình thì bạn sẽ có câu trả lời
a. 1 + 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256
= 1 + ( 1 - 1/2) + ( 1/2 - 1/4) + ( 1/4 - 1/8) + ( 1/8 - 1/16) + ( 1/16 - 1/32) + (1/32 - 1/64) + ( 1/64 - 1/128) + (1/128 - 1/256)
= 1 + 1 - 1/2 + 1/2 - 1/4 + 1/4 - 1/8 + 1/8 - 1/16 + 1/16 - 1/32 + 1/32 - 1/64 + 1/64 - 1/128 + 1/128 - 1/256
= 2 - 1/256
= 511/256
Câu b bạn có viết sai đề không vậy?
b, 3/1x4 + 3/2x5 + 3/3x6 + 3/4x7 + 1/5x8
= 3/4 + 3/10 + 3/18 + 3/28 + 1/40
= 1133/840
c,2/1x3 + 2/3x5 + 2/5x7+..+ 2/2001x2003 + 2/2003x2005
= ( 1 - 1/3) + ( 1/3 - 1/5) + ( 1/5 - 1/7) +...+ ( 1/2001 - 1/2003) + (1/2003 - 1/2005)
= 1 - 1/3 + 1/3 - 1/5 + 1/5 - 1/7 +...+ 1/2001 - 1/2003 + 1/2003 - 1/2005
= 1 - 1/2005
= 2004/2005
Tính theo mẫu:
Mẫu: 2dam + 3dam = 5dam
25dam + 50dam =
8dam + 12dam =
36dam + 18dam =
24dam – 10dam = 14dam
45dam – 16dam =
67 dam – 25dam =
72dam – 48dam =
25dam + 50dam = 75dam
8dam + 12dam = 20dam
36dam + 18dam = 54dam
45dam – 16dam = 29dam
67 dam – 25dam = 42dam
72dam – 48dam = 24dam.
Tính nhanh
a 2\9+1\5+7\9+4\5
b19\37+(1+19\37)
c 9\8-(17/7-3/7)+7/8
d 3/5x8/27x5/3
e 7/19x1/3+7/19x2/3
f 12/5x4-4x7/5 trả lời nhanh tick luôn
a) \(\frac{2}{9}+\frac{1}{5}+\frac{7}{9}+\frac{4}{5}=\left(\frac{2}{9}+\frac{7}{9}\right)+\left(\frac{1}{5}+\frac{4}{5}\right)= 1+1=2 \)
b) \(\frac{19}{37}+\left(1+\frac{19}{37}\right)=\left(\frac{19}{37}-\frac{19}{37}\right)+1=0+1=1\)
c) \(\frac{9}{8}-\left(\frac{17}{7}-\frac{3}{7}\right)+\frac{7}{8}=\frac{9}{8}+\frac{7}{8}-\left(\frac{17}{7}-\frac{3}{7}\right)=2-2=0\)
d) \(\frac{3}{5}\times\frac{8}{27}\times\frac{5}{3}=\frac{3}{5}\times\frac{5}{3}\times\frac{8}{27}=1\times\frac{8}{27}=\frac{8}{27}\)
e) \(\frac{7}{19}\times\frac{1}{3}+\frac{7}{19}\times\frac{2}{3}=\frac{7}{19}\times\left(\frac{1}{3}+\frac{2}{3}\right)=\frac{7}{19}\times1=\frac{7}{19}\)
f) \(\frac{12}{5}\times4-4\times\frac{7}{5}=4\times\left(\frac{12}{5}-\frac{7}{5}\right)=4\times1=4\)
94+23=
469+545948=
2000g=...kg
27:9=
4x7=
5x5=
94+23=117
469+545948=546417
2000g=2kg
27:9=3
4x7=28
5x5=25
94+23=117
469+545948=546417
2000g=2 kg
27:9=3
4x7=28
5x5=25
ai k mình
mình k lại
94+23=117
469+545948=546417
2000g=2kg
27:9=3
4X7-27
5X5=25
Tính theo mẫu:
25dam + 50dam =
25dam\(^2\)7m\(^2\)=.....dam\(^2\)
\(25dam^27m^2=25,7dam^2\)
Tính theo mẫu:
67 dam – 25dam =