198 : [130 – (27 – 19 )^2] + 2021^0
198:(130-(27-19)^2)+2021^0
a) - 23+150(-9)+1913
b) 2 MŨ2 .5 + ( 49 – 17 MŨ 2 )
c) 25. 69 + 31. 25 – 150; d) 198 : [130 – (27 – 19 ) MŨ 2] + 2021 MŨ 0
198:[130-(27-19)2 ]+20210
= 198 : [130 - 64 ] +1
= 198 : 66 + 1
= 3 + 1
= 4
=198:[130-(27-19)2 ]+1
=198:[130-64]+1
=198:66+1
=3+1=4
Bài 1: Thực hiện phép tính:
a) 25. 69 + 31. 25 – 150; b) 198 : [130 – (27 – 19 )2] + 20210 ;
c) 520 : (515.15 + 515.10).
a) 25.69+31.25-25.6
= 25.(69+31-6)
= 25.94
= 2350
b) 198:[130-(27-19)2]+20210
= 198:[130-82]+1
= 198:(130-64)+1
= 198:66+1
= 3+1
= 4
c) 520:[515.(15+10)]
= 520:[515.25]
= 520:(515.52)
= 520: 517
= 53
a) 25. 69 + 31. 25 – 150;
b) 198 : [130 – (27 – 19 )2] + 20210 ;
c) 520 : (515.15 + 515.10).
d) 27– (15 – 31) – (– 2 + 21+ 5)
e) 47 – (23 + 17) – (– 17 + 47)
f) 34 – [(–12) + 34] – (49 + 12) g) 72 – (15 – 14 + 72) + 52
a: =25x100-150=2500-150=2350
c: \(=520:\left\{515\cdot25\right\}\)
=104/2575
2.(38.13 13.11) : 27 - 2021 mũ 0
\(=2\cdot13\cdot27:27-1\)
=26-1
=25
h) 2.(38.13 - 13.11): 27 - 2021 mũ 0
\(=26\left(38-11\right):27-1\)
=26-1
=25
Tính hợp lý:
a) A=\(2021^2\)-2020.(2021+1)
b) B=1+2-3-4+5+6-7-8+9+10-...+2018-2019-2020+2021
c) C=\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}\)
a)= 2021.2021-2020.(2021+1)
= 2021.(2020+1)-2020.(2021+1)
= (2021.2020)+2021-(2020.2021)-2020
= 1
b) B= (1+2-3-4)+(5+6-7-8)+(9+10-11-12)...........+(2017+2018-2019-2020)+2021
B= -4+(-4)+....................(-4)+2021
B= -4x505+2021
B= -2020 + 2021
B = 1
83 + (-29 ) + 27 - 171
5 mũ 9 : 5 mũ 7 + 2. ( 23 + 2 ) - 2021 mũ 0