a)58×75+58×50-58×25
b)13,6+14,5+15,4-4,5-3,6-5,4
c)0,2×17×9×0,18×540×29×1,8
d)5+8+11+14+......+41
Tính nhanh:
a. 13,6 + 14,5 + 15,4 – 4,5 – 3,6 – 5,4
b. 0,2 x 17 x 9 + 0,18 x 540 + 29 x 1,8
a.=(13,6-3,6)+(14,5-4,5)+(15,4-5,4)
=10+10+10
=30
tính bằng cách hợp lý;
a, 14:(4 và 2/- 1 và 5/9)+14:(2/+8/9)
b, 13,6+14,5+15,4-4,5-3,6-5,4
em đang cần gấp
* Check lại đề câu a) nhé
b) 13,6 + 14,5 + 15,4 - 4,5 - 3,6 - 5,4
= ( 13,6 - 3,6 ) + ( 14,5 - 4,5 ) + ( 15,4 - 5,4 )
= 10 + 10 + 10
= 30
Bài 4: Tính nhanh
1/ 5 . 25 . 2 . 16 . 4 2/ 25 . 5 . 4 . 27 . 2 3/ 23 . 17 - 23 . 17 4/ 58 .75 + 58 . 50 – 58 . 25 | 5/ 125 . 98 – 125 . 46 – 52 . 25 6/ 136 . 23 + 136 . 17 – 40 . 36 7/ 5 . 23 + 35 . 41 + 64 . 65 8/ 29 . 87 – 29 . 23 + 64 . 71 |
a.58 . 75 + 58 . 50 - 58 . 25
b.20 : 22 - 59 : 58
c. ( 519 : 517- 4 ) : 7
a/ \(58.75+58.50-58.25\)
\(=58\left(75+50-25\right)\)
\(=58.100\)
\(=5800\)
b/ \(20\div2^2-5^9\div5^8\)
\(=20\div4-5\)
\(=5-5\)
\(=0\)
c/ \(\left(5^{19}\div5^{17}-4\right)\div7\)
\(=\left(5^2-4\right)\div7\)
\(=\left(25-4\right)\div7\)
\(=21\div7\)
\(=3\)
\(\dfrac{15}{17}\) x \(\dfrac{34}{5}\) < x < \(\dfrac{62}{15}\) + \(\dfrac{58}{15}\)
\(\dfrac{20}{29}\) x \(\dfrac{58}{5}\) < x < \(\dfrac{75}{11}\) + \(\dfrac{37}{11}\)
a: =>15/5*34/17<x<120/15
=>6<x<8
=>x=7
b; =>20/5*58/29<x<112/11
=>8<x<112/11
=>x=9 hoặc x=10
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39+40+41+42+43+44+45+46+47+48+49+50+51+52+53+54+56+57+58+59+60+61+62+63+64+65+66+67+68+69+70=?
(4 5/58 - 3 1/2 + 8 15/29)-(3 5/58 - 7 14/29)
\(=4+\dfrac{5}{58}-3-\dfrac{1}{2}+8+\dfrac{15}{29}-3-\dfrac{5}{58}+7+\dfrac{14}{29}=13+\dfrac{1}{2}=\dfrac{27}{2}\)
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