14/9 - 23/54 : 46/6
90+67+54+23+87+98+14+78+46+28=?
90 + 67 + 54 + 23 + 87 + 98 + 14 + 78 + 46 + 28
= 585
Chúc bạn hk tốt ~
26+17+23+14 46+2+18+54
26 + 17 + 23 + 14
= ( 26 +14 ) + ( 17 +23 )
= 40 + 40
= 80
46 + 2 + 18 + 54
= ( 46 + 54 ) + ( 18 + 2 )
= 100 + 20
=120
4, -5/6 - 26/5 . 1/13
5, (19/23 - 22/46) . 23/16
6, (3/4 . - 5/7) . (20/9 . - 14/15)
325+172-72+65 214+(-54)+(-14)+(-46)
245-[(32-22).10-5] 25.23-(9-14)+(29-34+20)
325+172-72+65
= (325 + 65) + (172 - 72)
= 390 + 100
= 490
214+(-54)+(-14)+(-46)
= (214 - 14) - (54+46)
= 200 - 100
= 100
245-[(32-22).10-5]
= 245 - [(9 - 4). 10 - 5]
= 245 - [5.10 - 5]
= 245 - [50 - 5]
= 245 - 45
= 200
25.23-(9-14)+(29-34+20)
= 25. 8 + (29 - 9) - (34 - 20 - 14)
= 200 + 20 - 0
= 220
11 tính nhanh
a. -37 + 54 + -70+ -163 + 246
b. -359+ 181+ -123+ 350+ -172
c.-69+ 53+ 46+ -94+-14+ 78
d. 13- 12+ 11+10- 9+ 8- 7- 6+ 5- 4+ 3+2- 1
a. -37 + 54 + -70+ -163 + 246
= ( 54 + 246) + (-37 - 163 ) - 70
= 300 -200 - 70 = 30
b. -359+ 181+ -123+ 350+ -172
=(-178)+227+(-172)
=49+(-172)
=-123
c.-69+ 53+ 46+ -94+-14+ 78
=(-16)+(-48)+64
=-64+64
=0
d. 13- 12+ 11+10- 9+ 8- 7- 6+ 5- 4+ 3+2- 1
= 13 - (13 - 1) + (13 - 2) + (13 - 3) - (13 - 4) + (13 - 5) - (13 - 6) - (13 - 7) + (13 - 8) - (13 - 9) + (13 - 10) + (13 - 11) - (13 - 12)
= 13 - 13 + 1 + 13 - 2 + 13 - 3 - 13 + 4 + 13 - 5 - 13 + 6 - 13 + 7 + 13 - 8 - 13 + 9 + 13 - 10 + 13 - 11 - 13 + 12
= (13 - 13 + 13 + 13 - 13 + 13 - 13 - 13 + 13 - 13 + 13 + 13 - 13) + (1 - 2 - 3 + 4 - 5 + 6 + 7 - 8 + 9 - 10 - 11 = 12)
= 13 + 0
= 13
a) \(-37+54+\left(-70\right)+\left(-163\right)+246\)
\(=\left(246+54\right)-\left(37+163\right)-70\)
\(=300-200-70\)
\(=100-70=30\)
b) \(-359+181+\left(-123\right)+350+\left(-172\right)\)
\(=-359+181-123+350-172\)
\(=\left(-359+350\right)+\left(181-172\right)-123\)
\(=-9+9-123\)
\(=-123\)
c) \(-69+53+46+\left(-94\right)+\left(-14\right)+78\)
\(=-69+53+46-94-14+78\)
\(=\left(-69+78\right)+\left(53-14\right)+\left(46-94\right)\)
\(=9+39-48\)
\(=48-48=0\)
d) \(13-12+11+10-9+8-7-6+5-4+3+2-1\)
\(=\left(13-12\right)+\left(11+10\right)-\left(9-8\right)-\left(7+6\right)+\left(5-4\right)+\left(3+2-1\right)\)
\(=1+21-1-13+1+5\)
\(=21-13+1+5\)
\(=8+1+5=9+5=14\)
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=?
Tính nhanh:
a) -37 +54 +(- 70)+(- 163)+246
b)-359 +181+(-123)+350+(-172)
c)-69 +53 + 46 +(- 94)+(- 14) + 78
d)13 -12 +11 +10 -9 + 8 -7 -6 +5 - 4 +3 +2 -1
a: =17-70-163+246
=-43-163+246
=246-206
=40