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222-9+11+12:2*14+14 = ? ( )

Toán Lớp 6: Bài 6: Thực hiện phép tính (tính nhanh nếu có thể) a) 81 + 243 + 19 b) 32 . 47 + 32 . 53 c) 20 – [30 – (5 – 1)2] d) 36 : 32 + 23 . 2

Toán Lớp 6: Bài 6: Thực hiện phép tính (tính nhanh nếu có thể)
a) 81 + 243 + 19 b) 32 . 47 + 32 . 53 c) 20 – [30 – (5 – 1)2]
d) 36 : 32 + 23 . 22 e) 80 – (4.52 – 3.23) f) 62 : 4 . 3 + 2 . 52
g) (–17) + 5 + 8 + 17 h) (–4) + (–440) + (–6) + 440 i) (–1075) – (29 – 1075)
k) 12 : {390 : [500 – (125 + 35 . 7)]} l) ( –21) + 2021 + 34 . 20220 – 2021.
m) 1 + (–2) + 3 + (–4) + 5 + (–6) + … + (–40)

Comments ( 1 )

  1. a) 81 + 243 + 19
    = (81 + 19) + 243
    = 100 + 243
    = 343
    b) 32 × 47 + 32 × 53
    = 32 × (47 + 53)
    = 32 × 100
    = 3200
    c) 20 – [30 – (5 – 1)$^{2}$] 
    = 20 – [30 – $4^{2}$]
    = 20 – [30 – 16]
    = 20 – 14
    = 6
    d) 36 : 32 + 23 × 22
    = 1,125 + 506
    = 507,125
    e) 80 – (4 × 52 – 3 × 23)
    = 80 – (208 – 69)
    = 80 – 139
    =  -59
    f) 62 : 4 × 3 + 2 × 52
    = 46,5 + 104
    = 150,5
    g) (-17) + 5 + 8 + 17
    = [(-17) + 17] + (5 + 8)
    = 0 + 13
    = 13
    h) (-4) + (-440) + (-6) + 440
    = [(-4) + (-6)] + [(-440) + 440]
    = (-10) + 0
    =  -10
    i) (-1075) – (29 – 1075)
    = (-1075) – 29 + 1075
    = [(-1075) + 1075] – 29
    = 0 – 29
    =  -29
    k) 12 : {390 : [500 – (125 + 35 × 7)]}
    = 12 : {390 : [500 – (125 +  245)]}
    = 12 : {390 : [500 – 370]}
    = 12 : {390 : 130}
    = 12 : 3
    = 4
    l) (-21) + 2021 + 34 × 2020 – 2021
    = (-21) + 2021 + 68  680 – 2021
    = (-21) + 68  680 + (2021 – 2021)
    = 68  659 + 0
    = 68  659
    m) 1 + (-2) + 3 + (-4) + 5 + (-6) + … + (-40)
    = [1 + (-2)] + [3 + (-4)] + [5 + (-6)] + … + 39 + (-40)
    = $\underbrace{(-1) + (-1) + (-1) + … + (-1)}_{\text{39 số hạng}}$
    = (-1) × 39
    =  -39

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222-9+11+12:2*14+14 = ? ( )

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