1. \(\text{5 + [- (-12) + (-9)] - [7 - (-10) + 3].}\)
\(=5+\left(12-9\right)-\left(7+10+3\right).\)
\(=5+3-20=-12.\)
2. \(\text{(− 28) + (-35) - 92 + (-82).}\)
\(-28-35-92-82=-237.\)
5+[-(-12)+(-9)]-[7-(-10)+3]
(− 28)+(-35)-92+(-82)
Bỏ dấu ngoặc rồi tính các tổng sau (từ Bài 3.20 đến Bài 3.21)
3.20.a)(-28)+(-35)-92+(-82)
b)15-(-38)+(-55)-(+47)
3.21.a)(62-81)-(12-59+9)
b)39+(13-26)-(62+39)
giúp mik với làm chi tiết nhé
(-28) + ( -35 ) - 92 + ( - 82 )
15 - ( - 38 ) + ( -55 ) - 47
107 – {38 + [7.32 – 24 : 6+(9 – 7)3]}:15
17) 10 – [(82 – 48).5 + (23.10 + 8)] : 28 - 70
Bỏ dấu ngoặc rồi tính các tổng sau
a) (−28)+(−35)−92+(−82) b) 15−(−38)+(−55)−47
Tính nhanh:
1) 69.(− 74)−31.74
2) (− 2020).35− 2020.65
3) − 23.59 −159.23
4) −147.47+ (− 47).(− 47)−300
5) (− 72).30 −31.−30 + 3.+ 30
6) (−82).(−55)+ (−82)+ (− 46).(−82)
7) (− 41).135+135.(− 24)−35.(−65)
8) 125.( 2) .( 25).9.( 10) .4 3 0 − − −
9) ( 2) .( 25).( 125).( 2) .2.( 50) 2 3 − − + − −
10) 125.(−88)
-10/3 + 13/10-1/6+7/10
1-20/6 +39/30-4/24+34/50
15/24-6/26+28/48-30/39+10/24
-5/10+12/28-3/27-7/18+20/35
a,9/4-[-11}/-4
b, 7/8-3/-8-1/8
c,-5/21-25/21-[-1]/21
d, 18/24-35/-10
e, 3/7-11/14-19/28
g, 5/-{-2}/3-1/12
h, 3/17-{-5}/13-{-18}/35-14/17-17/{-35}-{-8}/13
