.3. Tính nhanh a) (–219) + 263 + 319 + (–163) b) (–125).25.(–8).(–4).123 c) (225 – 1576) – (125 – 1576 + 176) d) 63 – 9.(10 + 7) e) 45.( –69) + 31.(–4

Bởi

.3. Tính nhanh
a) (–219) + 263 + 319 + (–163) b) (–125).25.(–8).(–4).123
c) (225 – 1576) – (125 – 1576 + 176) d) 63 – 9.(10 + 7)
e) 45.( –69) + 31.(–45) + (–27) g) (–23).(–48) – 23.148 – 245
h) 47.(27 – 15) – 27.(47 – 15) i) 162 (73 49) (73 162)

0 bình luận về “.3. Tính nhanh a) (–219) + 263 + 319 + (–163) b) (–125).25.(–8).(–4).123 c) (225 – 1576) – (125 – 1576 + 176) d) 63 – 9.(10 + 7) e) 45.( –69) + 31.(–4”

  1. a) $(–219) + 263 + 319 + (–163)$

    $= [(-219) + 319] + [263 + (-163)$

    $= 100 + 100$

    $= 200$

    b) $(–125) × 25 × (–8) × (–4) × 123$

    $=  [(-125) × (-8)] × [25 × (-4)] × 123$

    $= 1000 × 100 × 123$

    $= 100000 × 123$

    $= 12300000$

    c) $(225 – 1576) – (125 – 1576 + 176)$

    $= 225 – 1576 – 125 – 1576 – 176$

    $= (225 – 125) + (1576 – 1576) – 176$

    $= 100 – 176$

    $= -76$

    d) $63 – 9 × (10 + 7)$

    $= 63 – 90 – 63$

    $= -90$

    e) $45 × ( –69) + 31 × (–45) + (–27)$

    $= 45 × (-69 – 31) + (-27)$

    $= 45 × (-100) – 27$

    $= -4500 – 27$

    $= -4527$

    g) $(–23) × (–48) – 23 × 148 – 245$

    $= (-23) × (-48 + 148) – 245$

    $= (-23) × 100 – 245$

    $= -2300 – 245$

    $= -2545$

    h) $47 × (27 – 15) – 27 × (47 – 15)$

    $= 47 × 27 – 47 × 15 – 27 × 47 + 27 × 15$

    $= ( 47 × 27 – 27 × 47) + 15 × (27 – 47)$

    $= 0 + 15 × (-20)$

    $= -300$

    i) $62 – (73 – 49) + (73 – 162)$

    $= 62 – 73 + 49 + 73 – 162$

    $= (62 – 162) + [(-73) + 73] + 49$

    $= (-100) + 0 + 49$

    $= (-100) + 49$

    $= -51$

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  2. Đáp án:

    a) (–219) + 263 + 319 + (–163)

    = [(-219) + 319] + [236 + (-163)]

    = 100 + 100

    = 200

    b) (–125).25.(–8).(–4).123

    = [(-125). (-8)] . [(25 . (-4)] . 123

    = 1000 . (-100) . 123

     = -12300000

    c) (225 – 1576) – (125 – 1576 + 176)

    = 225 – 1576 – 125 + 1576 – 176

    = (225 – 125) + (1576 – 1576) – 176

    = 100 -176

    = -76

    d) 63 – 9.(10 + 7)

    = 63 – 90 – 63

    = -90

    e) 45.( –69) + 31.(–45) + (–27)

    = 45 . (-69 – 31) + (-27)

    = 45 . (-100) – 27

    = -4500 – 27

    = – 4527

    g) (–23).(–48) – 23.148 – 245

    = (-23) . (-48 + 148) – 245

    = (-23) . 100 – 245

    = -2300 – 245

    = -2545

    h) 47.(27 – 15) – 27.(47 – 15)

    = 47 . 27 – 47 . 15 – 27 . 47 + 27 . 15

    = ( 47 . 27 – 27 . 47) + 15 . (27 – 47)

    = 0 + 15 . (-20)

    = -300

    i) 162 (73 49) (73 162) ( câu này tất cả là dấu nhân à em?)

    = 

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