Giúp mình với mà đúng mới like nhé
A/ 15/34+7/21+19/37-20/15+3/7
B/ 3/8.27/1/5-51/1/5.3/8+19
C/ -2/7.21/8.-7/2
4.24.5^2-(3^3.18+3^3.12)
31.15.7^2.4-31.49.40
1+2+3+4+5+6+7+8+9+10
1+3+5+7+9+11+13+15+19
2+6+10+14+22+23+26+34
5+8+11+14+17+20+23+26+29
1+6+11+16+21+26+31+36+41+47+51
10+13+16+19+22+25+28+31+34+37+40
5+7+9+11+13+15+17+3+8+13+18+23+28
4+7+10+13+16+19+5+9+13+17+21+25
4.24.52-(33.18+33.12)
=4.24.25-[27.(18+12)]
=(4.25).24-[27.30]
=100.24-810
=2400-810
=1590
4.24.5^2-(3^3.18+3^3.12)
31.15.7^2.4-31.49.40
1+2+3+4+5+6+7+8+9+10
1+3+5+7+9+11+13+15+19
2+6+10+14+22+23+26+34
5+8+11+14+17+20+23+26+29
1+6+11+16+21+26+31+36+41+47+51
10+13+16+19+22+25+28+31+34+37+40
5+7+9+11+13+15+17+3+8+13+18+23+28
4+7+10+13+16+19+5+9+13+17+21+25 = 1590
#HT#
1) 5/7.37 13/23-51 13/23.5/7
2) -2/3 +1/3+0,5+2 1/2
3)-0,5+2/3+1/2
4) (8+2 1/3-3/5) -(5+0,4)-(3 1/2 -2)
5) (2/9-7/12):3/4+(16/9-5/12):3/4
6) -(2021.0,7+19,75) +0,7- (8-19,75)
7)15/34+7/21+19/34-20/15
8) 2 5/6+1/6:(-5/8)
9) (-2)^2 +2/9. (4/5-2/3)
10) (-1/5+3/7):5/4+(-4/5+4/7):5/4
11) 2022,2021 . 1954,1945+ 2022,2021 . (-1954,1945)
12) -5,2 .72 +69,1 +5,2 . (-28)+(-1,1)
13) (7 -1/2-3/4) : (5-1/4-5/8)
14) (8+ 2 1/3 -3/5) -(5+0,4) -( 3 1/3 - 2)
`@` `\text {Ans}`
`\downarrow`
`1)`
`5/7*37 13/23 - 51 13/23*5/7`
`= 5/7* (37 13/23 - 51 13/23)`
`= 5/7* (-14)`
`= -10`
`2)`
`-2/3 +1/3+0,5+2 1/2`
`= -2/3 + 1/3 + 1/2 + 5/2`
`= (-2/3+1/3) + (1/2+5/2)`
`= -1/3 + 3`
`=8/3`
`3)`
`-0,5+2/3+1/2`
`= -1/2 + 2/3 + 1/2`
`= (-1/2 + 1/2) + 2/3`
`= 2/3`
`4)`
`(8+2 1/3-3/5) -(5+0,4)-(3 1/2 -2)`
`= 8+ 7/3 - 3/5 - 5 - 0,4 - 7/2 + 2`
`= (8+2-5) + (-3/5 - 2/5) + (7/3 - 7/2)`
`= 5 - 1 - 7/6`
`= 4 - 7/6 = 17/6`
`5)`
`(2/9-7/12):3/4+(16/9-5/12):3/4`
`= (2/9 - 7/12) \times 4/3 + (16/9 - 5/12) \times 4/3`
`= 4/3 *(2/9 - 7/12 + 16/9 - 5/12)`
`= 4/3 * [(2/9 + 16/9) + (-7/12 - 5/12)]`
`= 4/3 * ( 2 - 1)`
`= 4/3 * 1 = 4/3`
`6)`
`-(2021.0,7+19,75) +0,7- (8-19,75)`
`= -2021*0,7 -19,75 + 0,7 - 8 + 19,75`
`= 0,7*(-2021 + 1) - 8`
`= -1414-8`
`= -1422`
`7)`
`15/34+7/21+19/34-20/15`
`= (15/34 + 19/34) + 7/21 - 20/15`
`= 1 + 7/21 - 20/15`
`= 4/3 - 20/15 =0`
`8)`
`2 5/6+1/6:(-5/8)`
`= 17/6 + (-4/15)`
`= 77/30`
`9)`
`(-2)^2 +2/9. (4/5-2/3)`
`= 4 + 2/9*2/15`
`= 4+4/135`
`= 544/135`
`10)`
`(-1/5+3/7):5/4+(-4/5+4/7):5/4`
`= (-1/5+3/7) * 4/5 + (-4/5+4/7) * 4/5`
`= 4/5*(-1/5 +3/7-4/5+4/7)`
`= 4/5*[(-1/5-4/5)+(3/7+4/7)]`
`= 4/5* (-1+1)`
`= 4/5*0=0`
`11)`
`2022,2021 . 1954,1945+ 2022,2021 . (-1954,1945)`
`= 2022,2021 * [1954,1945 + (-1954,1945)]`
`= 2022,2021*0 `
`= 0`
`12)`
`-5,2 .72 +69,1 +5,2 . (-28)+(-1,1)`
`= -5,2*72 + 69,1 - 5,2*28 - 1,1`
`= -5,2*(72+28) + (69,1 - 1,1)`
`= -5,2*100 + 68`
`= -520 + 68`
`= -452`
`13)`
`(7 -1/2-3/4) : (5-1/4-5/8)`
`= 23/4 \div 33/8`
`=46/33`
`14)`
`(8+ 2 1/3 -3/5) -(5+0,4) -( 3 1/3 - 2)`
`= 8+ 2 1/3 - 3/5 - 5 - 0,4 - 3 1/3 + 2`
`= (8+2-5) + (2 1/3 - 3 1/3) - (0,6 + 0,4) `
`= 5 - 1 - 1`
`= 3`
2: \(=\dfrac{-1}{3}+3=\dfrac{8}{3}\)
3: =1/2-1/2+2/3=2/3
5: \(=\dfrac{4}{3}\left(\dfrac{2}{9}-\dfrac{7}{12}+\dfrac{16}{9}-\dfrac{5}{12}\right)=\dfrac{4}{3}\)
12: \(=5.2\left(-72-28\right)+68=-520+68=-452\)
13: \(\dfrac{23}{4}:\dfrac{33}{8}=\dfrac{46}{33}\)
bài 437 Tính nhanh 13. -3/11 . -22/66 . 121/15 17. 1/3 . 4/5 + 1/3 . 6/5 18. 6/7 . 8/13 +6/13 . 9/7 - 3/13 . 6/7 19. -1/4 . 152/11 + 68/4 . -1/11 20. 3/7 . 9/26 - 1/14 . 1/13 21. 15(1/5 - 7/15) 22. 34(2và1/17 - 3và5/34)
Giúp mình với ạ
tính :
a, 7/4 + 5/-6+21/8
b,4/9+ (-7)/12 +8/15
c,-1/3 + 2 5/6 + 19/12
giúp mình với
Lời giải:
a.
$\frac{7}{4}+\frac{5}{-6}+\frac{21}{8}=\frac{42}{24}+\frac{-20}{24}+\frac{63}{24}=\frac{85}{24}$
b.
$\frac{4}{9}+\frac{-7}{12}+\frac{8}{15}$
$=\frac{80}{180}+\frac{-105}{180}+\frac{96}{180}=\frac{71}{180}$
c.
$=\frac{-1}{3}+\frac{5}{6}+\frac{19}{12}+2$
$=\frac{-4}{12}+\frac{10}{12}+\frac{19}{12}+2=\frac{25}{12}+2=\frac{49}{12}$
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=
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
=(1+37)x37:2
=703
Tính giá trị của biểu thức:
a, 15/34 +7/21+19/34-20/15+3/7
b, 12-8×(3/2)^3
c,(1/9)^2005×9^2005-96^2÷24^2
\(a,\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-\frac{20}{15}+\frac{3}{7}\)
\(=>\left(\frac{15}{34}+\frac{19}{34}\right)+\left(\frac{7}{21}+\frac{3}{7}\right)-\frac{20}{15}\)
\(=>1+\frac{16}{21}-\frac{20}{15}\)
\(=>\frac{37}{21}-\frac{20}{15}\)
\(=>\frac{3}{7}\)
\(b,12-8\cdot\left(\frac{3}{2}\right)^3\)
\(=>12-8\cdot\frac{27}{8}\)
\(=>12-27\)
\(=>-15\)
\(c,\left(\frac{1}{9}\right)^{2005}\cdot9^{2005}-96^2:24^2\)
\(=>\left(\frac{1^{2005}^{ }}{9^{2005}}\cdot9^{2005}\right)-\left(96^2:24^2\right)\)
\(=>\left(1^{2005}\right)-16\)
\(=>1-16\)
\(=>-15\)
a) (15-121/18):297/27-17/8:51/40=?
b) (-3,2)×(-15/64 )+(0,8-34/15):11/3=?
c) 6/7+5/8:5-3/16×(-2) mũ 2=?
d) (-5/24+0,75+7/12):(-7/8)=?
Giúp mình với nha!!
a; (15 - \(\dfrac{121}{18}\)) : \(\dfrac{297}{27}\) - \(\dfrac{17}{8}\) : \(\dfrac{51}{40}\)
(\(\dfrac{270}{18}\) - \(\dfrac{121}{18}\)) : \(\dfrac{297}{27}\) - \(\dfrac{17}{8}\) x \(\dfrac{40}{51}\)
= \(\dfrac{149}{18}\) : \(\dfrac{297}{27}\) - \(\dfrac{5}{3}\)
= \(\dfrac{149}{18}\) x \(\dfrac{27}{297}\) - \(\dfrac{5}{3}\)
= \(\dfrac{149}{198}\) - \(\dfrac{5}{3}\)
= \(\dfrac{149}{198}\) - \(\dfrac{330}{198}\)
= \(\dfrac{-181}{198}\)
b; (- 3,2) x (- \(\dfrac{15}{64}\)) + (0,8 - \(\dfrac{34}{15}\)): \(\dfrac{11}{3}\)
= (\(\dfrac{-16}{5}\)) x ( \(\dfrac{-15}{64}\)) + (\(\dfrac{4}{5}\) - \(\dfrac{34}{15}\)): \(\dfrac{11}{3}\)
= \(\dfrac{3}{4}\) + (\(\dfrac{4}{5}\) - \(\dfrac{34}{15}\)): \(\dfrac{11}{3}\)
= \(\dfrac{3}{4}\) + (\(\dfrac{12}{15}\) - \(\dfrac{34}{15}\)) : \(\dfrac{11}{3}\)
= \(\dfrac{3}{4}\) + \(\dfrac{-22}{15}\) : \(\dfrac{11}{3}\)
= \(\dfrac{3}{4}\) - \(\dfrac{22}{15}\) x \(\dfrac{3}{11}\)
= \(\dfrac{3}{4}\) - \(\dfrac{2}{5}\)
= \(\dfrac{15}{20}\) - \(\dfrac{8}{20}\)
= \(\dfrac{7}{20}\)
c; \(\dfrac{6}{7}\) + \(\dfrac{5}{8}\): 5 - \(\dfrac{3}{16}\) x (- 2)2
= \(\dfrac{6}{7}\) + \(\dfrac{5}{8}\) x \(\dfrac{1}{5}\) - \(\dfrac{3}{16}\) x 4
= \(\dfrac{6}{7}\) + \(\dfrac{1}{8}\) - \(\dfrac{3}{4}\)
= \(\dfrac{48}{56}\) + \(\dfrac{7}{56}\) - \(\dfrac{42}{56}\)
= \(\dfrac{55}{56}\) - \(\dfrac{42}{56}\)
= \(\dfrac{13}{56}\)
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
NHỚ KẾT BẠN VỚI MÌNH NHA '-'
1 + 2 + 3 +...+ 50
Dãy trên có số số hạng là:
\(\left(50-1\right)+1=50\) (số)
Tổng của chúng là:
\(\frac{\left(50+1\right)\cdot50}{2}=1275\)
Vậy tổng của chúng là 1275
~Học tốt~