a)-23+13-(-7)=-23+13+7=-23+(13+7)=-23+20=-(23-20)=-3
b)3.(-4)^2:(-12)+[-45-(-34+31)^3]=3.16:(-12)+[-45-(-3)^3]=48:(-12)+[-45+27]=-4+(-18)=-22
c)l-40l:8+4.(-2)-l+7l=40:8-8-7=5-8-7=-73-7=-10
Bài 1 : thực hiện phép tính
a, -23 + 13 - ( -7 )
b, | -40 | : 8 + 4 . ( -2 ) + | + 7 |
c, 3 . ( -4 ) 2 : ( -12 ) + ( -45 - ( -34 + 31 ) 3 )
Thuc hien phep tinh hop li(neu co the):
1) 69 .113 - 27. 69 + 69 .14 + 31
2) 90 -(22. 25 - 32. 7)
3) 720 - {40.[(120 - 70) :25 + 23]}
4) 2345 - 1000 :[19 - 2(21 - 18)2]
5) (-23) + 13 + (-17) + 57
6) (-123) + |-13| + (-7)
7) - |-33| +(-15)+ 20 - |45 - 40| - 57
a 12 – 34 b 23 – 47 c 31 – 23 d 9 – 5 e 4 – 15 25 f 23 13 17 57 g 4 . 9 6 . 12 – 7 h 14 6 19 14 19 i 56 – 8. 27 7 j 8 5 . 2 – 3 6 k 4 . 3 125 . 25 8 l 9 6 . 3 – 4 7 m 45. 18 – 15 – 18. 45 – 15
1..thuc hien phep tinh
a) [18-(-21)+(-9)]-13
b)125-139+200-(-75)
c) (-33)-(-12)-4
d) 22+(-31)-32+50
1) thuc hien phep tinh
a) 75-(3.52-4.23)
b)-/-12/+12-(-24)
c)17.85+15.17-120
2) tim x,biet
a)70-5.(x-3)=45
b)x-7=(-14)+(-8)
c)2./x-2/-4=6
d)128:22x-1=4
Thuc hien cac phep tinh sau một cách hợp lí:
a) (10^2 + 11^2 + 12^2) : (13^2 + 14^2)
b) 1.2.3...9-1.2.3...8-1.2.3...7.8^2
c) (3.4.2^16)^2/11.2^13.4^11-16^9
d) 1152 - (374 + 1152) +(-65 + 374)
e) 13-12+11+10-9+8-7-6+5-4+3+2-1
1) Thuc hien phep tinh:
a) 4^6 × 9^2 / 6^3 × 8^2
b) 5^6 × 15^4 /5^4 × 3^3
c) 3^9 - 2^3 × 3^7 + 2^10 × 3^2 - 2^13 / 3^10 - 2^2 × 3^7 + 2^10 × 3^3 - 2^12
d) (1/9)^10 : (1/3)^20
e) (1/64)^5 × (1/4)^7
2) Chung minh rang:
a)2014^100+2014^99 chia het cho 2015
b) 4^13+32^5-8^8 chia het cho 5
c) 81^27-27^9-9^13 chia het cho 405
Help me!! Pleass!!
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
1..tinh nhanh
22-(-23)-23.78
b) -83.36+17.(-36)
c) 30.(18-39)-39.(30-18)
2...thuc hien phep tinh
a) [18-(-21)+(-9)]-13
b)125-139+200-(-75)
c) (-33)-(-12)-4
d) 22+(-31)-32+50
giup mk xiu nha mk tick cho
