Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
1) \(\left(+15\right)+\left(+17\right)=15+17=32\)
2) \(\left(-3\right)+\left(-7\right)=-3-7=-\left(3+7\right)=-10\)
3) \(\left(-25\right)+\left(+4\right)=-25+4=-\left(25-4\right)=-21\)
4) \(\left(-6\right)+\left(-54\right)=-6-54=-\left(6+54\right)=-60\)
5) \(\left(-15\right)+20=20-15=5\)
6) \(\left(-5\right)+8+7+5\)
\(=\left(-5+5\right)+\left(8+7\right)\)
\(=15\)
7) \(\left(-8\right)+\left(-11\right)+\left(-2\right)\)
\(=\left[\left(-8\right)+\left(-2\right)\right]+\left(-11\right)\)
\(=\left(-10\right)+\left(-11\right)\)
\(=-21\)
8) \(15+\left(-5\right)+\left(-14\right)+\left(-16\right)\)
\(=\left[15+\left(-5\right)\right]+\left[\left(-14\right)+\left(-16\right)\right]\)
\(=10+\left(-30\right)\)
\(=-20\)
9) \(\left(-20\right)+\left(-14\right)+3+\left(-86\right)\)
\(=\left[\left(-20\right)+3\right]+\left[\left(-14\right)+\left(-86\right)\right]\)
\(=\left(-17\right)+\left(-100\right)\)
\(=-117\)
10) \(\left(-136\right)+123+\left(-264\right)+\left(-83\right)+240\)
\(=\left[\left(-136\right)+\left(-264\right)\right]+\left[123+\left(-83\right)\right]+240\)
\(=\left(-400\right)+40+240\)
\(=\left(-360\right)+240\)
\(=-120\)
11) \(\left(-596\right)+2001+1999+\left(-404+189\right)\)
\(=\left(-596\right)+2001+1999-404+189\)
\(=\left[\left(-596\right)-404\right]+\left(2001+189\right)+1999\)
\(=\left(-1000\right)+2190+1999\)
\(=1190+1999\)
\(=3189\)
12) \(314+\left(-153\right)+64+121+\left(-247\right)+218\)
\(=\left(314+64+121\right)+\left[\left(-153\right)+\left(-247\right)\right]+218\)
\(=\left(378+121\right)+\left(-400\right)+218\)
\(=499-400+218\)
\(=99+218\)
\(=317\)
\(\text{#}Toru\)
Bài 3 : a) 3784 + 23 - 3785 - 15
= (3784 - 3785) + (23 - 15)
= -1 + 8
= 7
b) 21 + 22 + 23 + 24 - 11 - 12 - 13 - 14
= (21 - 11) + (22 - 12) + (23 - 13) + (24 - 14)
= 10 + 10 + 10 + 10
= 40
Bài 4 : a) -2001 + (1999 + 2001)
= -2001 + 1999 + 2001
= ( - 2001 + 2001 ) + 1999
= 0 + 1999
= 1999
B) (43 - 863) - (137 - 57)
= 43 - 863 - 137 - 57
= (43 - 57) + ( -863 - 137 )
= -14 + -1000
= -1014
Nhớ tick !!!
tính = 1 cách hợp lí
a,-136+123+(-264)+(-83)+240
b,-596+2001+1999+(-404)+189
làm ơn mình đg cần gấp!
a,-136+123+(-264)+(-83)+240
= (123 - 83) - (136 + 264) + 240
= -40 - 400 + 240
= (240 - 40) - 400
= 200 - 400 = -200
b,-596+2001+1999+(-404)+189
= (2001 + 1999) - (596 + 404) + 189
= 4000 - 1000 + 189
= 3000 + 189
= 3189
1
a)1000-570-430+234
=1000-(570+430)+234
=1000-1000+234
=0+234
=234
b)-596+2001+1999-404+189
=2001+(1999-596-404)+189
= 2001+[1999-(596+404)+189
=2001+(1999-1000)+189
=2001+999+189
=3000+189
=3189
2
S1=1+(-3)+5+(-7)+...+17
=1-3+5-7+...+17
=(1-3)+(5-7)+(9-11)+(13+15)+17
=(-2)+(-2)+(-2)+(-2)+17
=(-8)+17
=9
S1=9
S2=-2+4+(-6)+8+...+(-18)
=[(-2)+4]+[(-6)+8]+[(-10)+12]+[(-14)+16]+(-18)
=2+2+2+2+(-18)
=8+(-18)
= -10
S2=-10
S1+S2=9+(-10)= -1
A=1-6+11-16+21-26+...........+1991-1996+2001-2006+2010
A=(1-6)+(11-16)+(21-26)+........+(1991-1996)+(2001-2006)+2010
A= -5+(-5)+(-5)+..........+(-5)+(-5)+2010
A=(-5).201+2010
A=-1005+2010
A=1005
1+2+3+4+5+6+7+8+9+10=55
11+12+13+14+15+16+17+18+19+20=155
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+30-50-53=362
a: \(=1125-374-1125-65+374=-65\)
b: \(=-2003+54+2003=54\)
c: \(=\left(942-1942\right)+\left(-2567+2563\right)=-4-1000=-1004\)
e: \(=\left(1000-570-430\right)+2341=2341\)
f: \(=\left(-596-404\right)+\left(2001+1999\right)+189\)
\(=3189\)
a) ( - 30 ) + ( - 29 ) + ( - 28 ) + ... + 48 + 49 + 50
= [ ( - 30 ) + 30 ] + [ ( - 29 ) + 29 ] + [ ( - 28 ) + 28 ] + ..... + 48 + 49 + 50
= 0 + 0 + 0 + .... + 31 + 32 + 33 + 34 + 35 + 36 + 37 + 38 + 39 + 40 + 41 + 42 + 43 + 44 + 45 + 46 + 47 + 48 + 49 + 50
= 31 + 32 + 33 + 34 + 35 + 36 + 37 + 38 + 39 + 40 + 41 + 42 + 43 + 44 + 45 + 46 + 47 + 48 + 49 + 50
= ( 31 + 49 ) + ( 32 + 48 ) + ( 33 + 47 ) + ( 34 + 46 ) + ( 35 + 45 ) + ( 36 + 44 ) + ( 37 + 43 ) + ( 38 + 42 ) + ( 39 + 41 ) + 50
= 80 + 80 + 80 + 80 + 80 + 80 + 80 + 80 + 80 + 50
= 80 . 9 + 50
= 720 + 50
= 770