1+2+3+4+5+6+9+9-8*5*58 = ?
bài 1 : tính :
6/7 + 5/8
3/5 - 58
1/4 + 5/6
4/9 - 1/6
\(\dfrac{6}{7}+\dfrac{5}{8}=\dfrac{48+35}{56}=\dfrac{53}{56}\)
\(\dfrac{3}{5}-58=\dfrac{3-290}{5}=\dfrac{-287}{5}\)
\(\dfrac{1}{4}+\dfrac{5}{6}=\dfrac{6+20}{24}=\dfrac{26}{24}=\dfrac{13}{12}\)
\(\dfrac{4}{9}-\dfrac{1}{6}=\dfrac{24-9}{54}=\dfrac{15}{54}\)
\(\dfrac{6}{7}\) + \(\dfrac{5}{8}\) = \(\dfrac{48}{56}\) + \(\dfrac{35}{56}\) = \(\dfrac{83}{56}\)
\(\dfrac{3}{5}\) - 58 (lớp 4 chưa học số âm xem lại đề )
\(\dfrac{1}{4}\) + \(\dfrac{5}{6}\) = \(\dfrac{3}{12}\) + \(\dfrac{10}{12}\) = \(\dfrac{13}{12}\)
\(\dfrac{4}{9}\) - \(\dfrac{1}{6}\) = \(\dfrac{8}{18}\) - \(\dfrac{3}{18}\) =\(\dfrac{5}{18}\)
a .(18 – 9 x 2) x (2 + 4 + 6 + 8 + 10)
b.(7 x 8 – 56 ) : (2 + 4 + 6 + 8 + 112)
c. (2 + 125 + 6 + 145 + 112) x (42 – 6 x 7)
d.(12 x 6 – 12 x 4 – 12 x 2) x ( 347 + 125)
e(a x 7 + a x 8 – a x 15) : (1 + 2 + 3 + ........ + 10)
f.58 – 58 x (6 + 54 – 60)
g.32 + 63 x a x ( a x 1 – a : 1) + 32 x 8 + 32
h.(1 + 2 + 3 + 4 + .... + 9) x (21 x 5 – 21 – 4 x21)
i.(9 x 7 + 8 x 9 – 15 x 9) : (1 + 3 + 5 + 7 + ........+ 17 + 19)
k.(2 + 4 + 6 + 8 + ... + 20) x (56 x 3 – 72 : 9 x 21)
1.(18 - 18) x (2 + 8) + ( 4 + 6) + 10 = 30
có rút gọn phân số 35/6 về phân số đc ko ? Nếu có thì mn rút gọn cho mik nhé !
Ai xong tr tui k cho
Tính nhẩm: 1) 373737 . 73 - 37 . 737373 2)19 . 41414141 - 41 . 19191919 3)123456 . 456789456789 - 456789 . 123456123456 4)250 . 12 . 7 5)24 . 125 . 9 6)125 . 44 . 18 7)8 . 24 . 6 + 12 . 4 . 52 + 2 . 22 . 24 8)18. 58 . 2 - 9 . 27 . 4 + 12 . 69 . 3 9)30 . 85 . 3 + 18 . 72 . 5 - 45 . 37 . 2 - 9 . 20 . 10
1) \(373737.73-37.737373\)
\(=37.10101.73-37.73.10101\)
\(=0\)
2) \(19.41414141-41.19191919\)
\(=19.41.1010101-41.19.1010101\)
\(=0\)
3) \(123456.456789456789-456789.123456123456\)
\(=123456.456789.1000001-456789.123456.1000001\)
\(=0\)
4) \(250.12.7\)
\(=250.4.3.7\)
\(=\left(250.4\right).\left(3.7\right)\)
\(=1000.21\)
\(=21000\)
5) \(24.125.9\)
\(=3.8.125.9\)
\(=\left(3.9\right).\left(8.125\right)\)
\(=27.1000\)
\(=27000\)
6) \(125.44.18\)
\(=125.4.11.2.9\)
\(=\left(125.4.2\right).\left(11.9\right)\)
\(=1000.99\)
\(=99000\)
7) \(8.24.6+12.4.52+2.22.24\)
\(=48.24+48.52+48.22\)
\(=48\left(24+52+22\right)\)
\(=48.98\)
\(=48\left(100-2\right)\)
\(=48.100-48.2\)
\(=4800-96\)
\(=4704\)
8) \(18.58.2-9.27.4+12.69.3\)
\(=36.58-36.27+36.69\)
\(=36\left(58-27+69\right)\)
\(=36.100=3600\)
9) \(30.85.3+18.72.5-45.37.2-9.20.10\)
\(=90.85+90.72-90.37-90.20\)
\(=90\left(85+72-37-20\right)\)
\(=90.100=9000\)
1+2+3-4-5-6+7+8+9+...+55+56+57-58-59-60
1+2+3-4-5-6+7+8+9+...+55+56+57-58-59-60
=(1+2+3-4-5-6)+(7+8+9-10-11-12)+.......+(55+56+57-58-59-60)
=(-9)+(-9)+......+(-9)
còn lại bạn làm theo cách tính tổng của dãy là đc
Tính
A=1*2+3*4+...+57*58
B=1*2*3+2*3*4+...+8*9*10
C=1*3*5+3*5*7+5*7*9+...+7*9*11
1+1+1+1+2+2+2+3+3+3+3+4+4+4+4+5+5+5+5+6+6+6+6+7+7+7+7+8+8+8+8+9+9+9+9+10=
= (1+1+1+1)+(2+2+2)+(3+3+3+3)+(4+4+4+4)+(5+5+5+5)+(6+6+6+6)+(7+7+7+7)+(8+8+8+8)+(9+9+9+9)+10
4 + 6 + 12 + 16 + 20 + 24 + 28 + 32 + 36 + 10 =
= 188
Tính:
8 + 1 = 7 + 2 = 6 + 3 = 5 + 4 =
1 + 8 = 2 + 7 = 3 + 6 = 4 + 5=
9 - 8 = 9 - 7 = 9 - 6 = 9 - 5 =
9 - 1 = 9 - 2 = 9 - 3 = 9 - 4 =
8 + 1 = 9 7 + 2 = 9 6 + 3 = 9 5 + 4 = 9
1 + 8 = 9 2 + 7 = 9 3 + 6 = 9 4 + 5= 9
9 - 8 = 1 9 - 7 = 2 9 - 6 = 3 9 - 5 = 4
9 - 1 = 8 9 - 2 = 7 9 - 3 = 6 9 - 4 = 5
1+2+3+4+5+6+7+8+9-1-2-3-4-5-6-7-8-9*1*2*3*4*5*6*7*8*9:1:2:3:4:5:6:7:8:9=???
14dm5cm=14,5dm;3dm7cm=3,7dm
chu vi hình chữ nhật đó là:
(14,5+3,7)x2=36,4(dm)
ĐS:36,4dm
14 dm 5 cm = 14,5 dm
3 dm 7 cm = 3,7 dm
Chiều rộng HCN là :
14,5 - 3,7 = 10,8 ( dm )
chu vi HCN là :
( 14,5 + 10,8 ) x 2 = 50,6 ( dm )
ĐS:..