So sánh các tích sau hợp lý nhất:
P = (-21/34).(-13/27).7/9
Q = (-0,5).3/19.(-24/41).(-8/31)
M = -6/17.-5/17. ... .5/17.6/17
1. So sánh các tích sau hợp lý nhất:
P = \(\left(-\dfrac{21}{34}\right)\)\(\left(-\dfrac{13}{27}\right)\)\(\dfrac{7}{9}\)
Q = \(\left(-0,5\right)\)\(\dfrac{3}{19}\)\(\left(-\dfrac{24}{41}\right)\)\(\left(\dfrac{8}{31}\right)\)
M = \(\dfrac{-6}{17}.\dfrac{-5}{17}.\) ... \(.\dfrac{5}{17}.\dfrac{6}{17}\)
2. Tính hợp lý:
A = \(\left(-\dfrac{3}{11}\right).\dfrac{7}{10}.\dfrac{11}{-13}.\left(-20\right)\)
B = \(\dfrac{-4}{9}:\dfrac{2}{13}+\left(\dfrac{-5}{18}\right).\dfrac{2}{13}\)
C = \(\left(2\dfrac{1}{15}.\dfrac{3}{19}.\dfrac{2}{31}\right):\left(-\dfrac{5}{19}\right)\)
Help me!
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+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=?
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=1275
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.
Có ai rảnh đâu mà đi ngồi cộng ngần đấy số ra.
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
Bài 1: Tính hợp lý
1/ 35.18-5.7.28
2/ 45-5.(12+9)
3/ 24.(16-5)-16.(24-5)
4/ 29.(19-13)-19.(29-13)
5/ 31.(-18)+31.(-81)-31
6/ (-12).47(-12).52+(-12)
7/ 13.(23+22)-3.(17+28)
8/ -48+48.(-78)+48.(21)
1, 35 . 18 - 5 . 7 . 28
= 35 . 18 - 35 . 28
= 35 . ( 18 - 28 )
= 35 . ( -10 )
= -350
2, 45 - 5 . ( 12 + 9 )
= 40 . 21
= 840
3, 24 . ( 16 - 5 ) - 16 . ( 24 - 5 )
= 24 . 11 - 16 . 19
= 264 - 304
= -40
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~
Bài 1:Tính:
a,3 14/19 + 13/17 + 35/43 + 6 5/19 + 8/13
b,130 25/28 + 120 17/35
c,17 2/31 - (15/17 + 6 2/31)
d,(31 6/13 + 5 9/41) - 31 6/13
e,(17 24/31 - 3 7/8) - (2 38/31 - 4)
g,1/1.2 + 1/2.3 + 1/3.4 + 1/4.5 + 1/5.6
h,1/1.2 + 1/2.3 + 1/3.4 + .........+ 1/49.100
i,1/1.3 + 1/3.5 + 1/5.7 +........+ 1/97.99