(-20)+18+(-2)
(-5).2+10
\(\left(0.25\right)^{10}\cdot4^{10}+\sqrt{5^2-3^2}\)
\(\dfrac{5}{20}+\dfrac{18}{11}-25\%-\left(\dfrac{18}{11}-\dfrac{4}{9}\right)\)
\(\left(0.25\right)^{10}.4^{10}+\sqrt{5^2-3^2}\)
\(=0.4^{10}+\sqrt{25-9}\)
\(=0+\sqrt{16}=0+4=4\)
\(\dfrac{5}{20}+\dfrac{18}{11}-25\%-\left(\dfrac{18}{11}-\dfrac{4}{9}\right)\)
\(=\dfrac{5}{20}+\dfrac{18}{11}-\dfrac{1}{4}-\dfrac{18}{11}+\dfrac{4}{9}\)
\(=\left(\dfrac{5}{20}-\dfrac{1}{4}\right)+\left(\dfrac{18}{11}-\dfrac{18}{11}\right)+\dfrac{4}{9}\)
\(=0+0+\dfrac{4}{9}=\dfrac{4}{9}\)
(0,25)10.410 + \(\sqrt{5^2-3^2}\)
= (0,25 .4)10 + \(\sqrt{25-9}\)
= 110 + \(\sqrt{16}\)
= 1 + 4
= 5
\(\dfrac{5}{20}\) + \(\dfrac{18}{11}\) - 25% - ( \(\dfrac{18}{11}\) - \(\dfrac{4}{9}\))
= 25% + \(\dfrac{18}{11}\) - 25% - \(\dfrac{18}{11}\) + \(\dfrac{4}{9}\)
= ( 25% - 25%) + ( \(\dfrac{18}{11}\) - \(\dfrac{18}{11}\)) + \(\dfrac{4}{9}\)
= 0 + 0 + \(\dfrac{4}{9}\)
= \(\dfrac{4}{9}\)
a) 35 l + 18 l 53 l - 35 l 53 l - 18 l
b) 5 kg x 2 10 kg : 2 10 kg : 5
c) 40 m + 20 m 60 m - 20 m 60 m - 40 m
a/ 35l + 18l = 53l 53l - 35l = 18l 53l - 18l = 35l
b/ 5 kg x 2 = 10 kg 10 kg : 2 = 5 kg 10 kg : 5 = 2 kg
c/ 40 m + 20 m = 60 m 60 m - 20 m = 40 m 60 m - 40 m = 20 m
a) 35l+18l=53l 53l-35l=18l 53l-18l=35l
b)5kgx2=10kg 10kg:2=5kg 10kg:5=2kg
c)40m+20m=60m 60m-20m=40m 60m-40m=20m
1a) 35 l + 18 l=53l 53 l - 35 l=18l 53 l - 18 l=35l`
1b) 5 kg xx 2=10kg 10 kg : 2=5kg 10 kg : 5=2kg`
1c) 40 m + 20 m=60m 60 m - 20 m=40m 60 m - 40 m=20m`
Tính 1) 4/5 +13/18 2) 3/7 -11/8 3) -7/10 - -4/5 4) 3/20 -1/25 5) 2/3 - 5/6 6) 1/4 + -3/8 - 19/10 7) -9/10 - -7/18 8) 3/10 - 11/18 9) 3/5 -5/6 + -7/12 10) -4/9 - (-5 )/6 - 3/8
1: =72/90+65/90=137/90
2: =24/56-77/56=-53/56
3: =-7/10+4/5=1/10
4: =15/100-4/100=11/100
5: =4/6-5/6=-1/6
6: =10/40-15/40-76/40=-81/40
7: =-9/10+7/18
=-81/90+35/90=-46/90=-23/45
8: =27/90-55/90=-28/90=-14/45
9: =36/60-50/60-35/60=-49/60
10: =-4/9+5/6-3/8
=-32/72+60/72-27/72
=1/72
\(1,\dfrac{4}{5}+\dfrac{13}{18}=\dfrac{72}{90}+\dfrac{65}{90}=\dfrac{137}{90}\)
\(2,\dfrac{3}{7}-\dfrac{11}{8}=\dfrac{24}{56}-\dfrac{77}{56}=\dfrac{-53}{56}\)
\(3,-\dfrac{7}{10}-\left(-\dfrac{4}{5}\right)=-\dfrac{7}{10}-\left(-\dfrac{8}{10}\right)=\dfrac{1}{10}\)
\(4,\dfrac{3}{20}-\dfrac{1}{25}=\dfrac{75}{500}-\dfrac{20}{500}=\dfrac{55}{500}=\dfrac{11}{100}\)
\(5,\dfrac{2}{3}-\dfrac{5}{6}=\dfrac{12}{18}-\dfrac{15}{18}=-\dfrac{3}{18}=-\dfrac{1}{6}\)
\(6,\dfrac{1}{4}+\left(-\dfrac{3}{8}\right)-\dfrac{19}{10}=\dfrac{8}{32}+\left(-\dfrac{12}{32}\right)-\dfrac{19}{10}=-\dfrac{4}{32}-\dfrac{19}{10}\)
\(=-\dfrac{1}{8}-\dfrac{19}{10}=-\dfrac{10}{80}-\dfrac{152}{80}=-\dfrac{162}{80}=-\dfrac{81}{40}\)
\(7,-\dfrac{9}{10}-\left(-\dfrac{7}{18}\right)=-\dfrac{162}{180}-\left(-\dfrac{70}{180}\right)=-\dfrac{92}{180}=-\dfrac{23}{45}\)
\(8,\dfrac{3}{10}-\dfrac{11}{18}=\dfrac{54}{180}-\dfrac{110}{180}=-\dfrac{56}{180}=-\dfrac{14}{45}\)
\(9,\dfrac{3}{5}-\dfrac{5}{6}+\left(-\dfrac{7}{12}\right)=\dfrac{18}{30}-\dfrac{25}{30}+\left(-\dfrac{7}{12}\right)=-\dfrac{7}{30}+\left(-\dfrac{7}{12}\right)\)
\(=-\dfrac{84}{360}+\left(-\dfrac{210}{360}\right)=-\dfrac{294}{360}=-\dfrac{49}{60}\)
\(10,-\dfrac{4}{9}-\dfrac{-5}{6}-\dfrac{3}{8}=-\dfrac{24}{54}-\dfrac{-45}{54}-\dfrac{3}{8}\)
\(=\dfrac{21}{54}-\dfrac{3}{8}=\dfrac{7}{18}-\dfrac{3}{8}=\dfrac{56}{144}-\dfrac{54}{144}=\dfrac{2}{144}=\dfrac{1}{72}\)
`@mt`
1+1+2+2+3+3+4+4+5+5+6+6+10+10+12+12+14+14+16+16+18+18+20+20+7+7+8+8+9+9
GIUP MK VOI MK TICK CHO NGUOI NHANH NHAT
1+1+2+2+3+3+4+4+5+5+6+6+7+7+8+8+9+9=2+4+6+8+10+12+14+16+18
=(2+8)+(4+6)+10+(12+18)+(14+16)
=10+10+10+30+30
=30+30+30
=30x3
=90
Mẫu: 60 : 20 = ( 60 : 10 ) : ( 20 : 10 ) = 6 :2 = 3
A) 75 : 25 = ( 75 : ..... ) : ( 25 : 5 ) = ..........................................................
B) 90 : 18 = ( 90 : ..... ) : ( 18 : 9 ) = ..........................................................
A) 75 : 25 = ( 75 : 5 ) : ( 25 : 5 ) = 15 : 5 = 3
B) 90 : 18 = ( 90 : 18 ) : ( 18 : 18 ) = 5 : 1 = 5
A) vì hai số đều chia hết cho 5 cho nên lấy hai số chia 5 ra kết quả bao nhiêu thì lấy hai số đó chia cho nhau
B) vì hai số đều chia hết cho 18 cho nên lấy hai số chia 18 ra kêt quả bao nhiêu thì lấy hai số chia cho nhau
Tính nhanh:A=1*5*6+2*10*12+3*15*18+4*20*24+5*25*30/1*3*5+2*6*10+3*9*15+4*12*20+5*15*25
ta có : (ghi lại đề)
=6+12+18+24+30/3+6+9+12+15
=2*(3/3+6/6+9/9+12/12+15/15)
=2*(1+1+1+1+1)
=2*5=10
chúc main học tốt nhé
Tìm x:
5\(^{10}\) : 5\(^8\) + x = 3\(^{20}\) : (-3)\(^{18}\) - 2\(^{35}\) : (-2)\(^{33}\)
\(5^{10}:5^8+x=3^{20}:\left(-3\right)^{18}-2^{35}:\left(-2\right)^{33}\\ \Leftrightarrow5^2+x=3^2+\left(-2\right)^2\\ \Leftrightarrow25+x=13\\ \Leftrightarrow x=-12\)
5^10/5^8+x=3^20/(-3)^18-2^35/(-2)^33
5^2+x=(-3)^2+2^2
25+x= 9+4
25+x=13
x=13-25
x=-12
vậy x=-12
E=1×2×3+2×3×4×3×4×5+...+18×19×20
G=2×4×6+4×6×8+6×8×10+...-18×20×22
H=1×3×5+3×5×7+5×7×9+17×19×21
\(E=1.2.3+2.3.4+3.4.5+...+18.19.20\)
\(4E=1.2.3.4+2.3.4.4+3.4.5.4+...+18.19.20.4\)
\(4E=1.2.3.4+2.3.4.\left(5-1\right)+3.4.5.\left(6-2\right)+...+18.19.20.\left(21-17\right)\)
\(4E=1.2.3.4+2.3.4.5-1.2.3.4+3.4.5.6-2.3.4.5+...+18.19.20.21-17.18.19.20\)
\(4E=18.19.20.21\)
\(4E=143640\)
\(E=\frac{143640}{4}\)
\(E=35910\)
Chúc bạn học tốt ~
\(G=2.4.6+4.6.8+6.8.10+...+18.20.22\) ( xem lại đề có nhầm dấu ko nha bn )
\(8G=2.4.6.8+4.6.8.8+6.8.10.8+...+18.20.22.8\)
\(8G=2.4.6.8+4.6.8.\left(10-2\right)+6.8.10.\left(12-4\right)+...+18.20.22\left(24-16\right)\)
\(8G=2.4.6.8+4.6.8.10-2.4.6.8+6.8.10.12-4.6.8.10+...+18.20.22.24-16.18.20.22\)
\(8G=18.20.22.24\)
\(8G=190080\)
\(G=\frac{190080}{8}\)
\(G=23760\)
Chúc bạn học tốt ~
\(H=1.3.5+3.5.7+5.7.9+...+17.19.21\)
\(8H=1.3.5.8+3.5.7.8+5.7.9.8+...+17.19.21.8\)
\(8H=1.3.5.8+3.5.7.\left(9-1\right)+5.7.9.\left(11-3\right)+...+17.19.21.\left(23-15\right)\)
\(8H=1.3.5.8+3.5.7.9-1.3.5.7+5.7.9.11-3.5.7.9+...+17.19.21.23-15.17.19.21\)
\(8H=1.3.5.8-1.3.5.7+17.19.21.23\)
\(8H=15+156009\)
\(8H=156024\)
\(H=\frac{156024}{8}\)
\(H=19503\)
Chúc bạn học tốt ~
5/15 + 3/12 + 2/10 + 18/27 + 12/16 + 20/25
\(\dfrac{5}{15}+\dfrac{3}{12}+\dfrac{2}{10}+\dfrac{18}{27}+\dfrac{12}{16}+\dfrac{20}{25}\)
\(=\dfrac{1}{3}+\dfrac{2}{3}+\dfrac{1}{4}+\dfrac{3}{4}+\dfrac{1}{5}+\dfrac{4}{5}\)
=3