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

Toán Lớp 8: Bài 1: phân tích đa thức thành nhân tử a) 5x (x – 2y) + 2 ( 2y – x ) b) 5x (x – 11 ) – 10y(x – 11 ) j) a2b4 + a3b – abc l)

Toán Lớp 8: Bài 1: phân tích đa thức thành nhân tử
a) 5x (x – 2y) + 2 ( 2y – x ) b) 5x (x – 11 ) – 10y(x – 11 )
j) a2b4 + a3b – abc l) 7x(y– 4)2 – (4 – y)3
k) – x2y2z – 6x3y – 8x4z2 – 9x5y5z5 m) x2 – x + 1 + 7x (x2 – x + 1)
f) x(x+y) – (2x+2y) g) 2x(x+y) – 10x – 10y
n) 5×5 (y3+3y – 13 ) – 4y (y3+3y – 13 ) – 2x(y3+3y – 13 )
Bài 2: Tính nhanh
a) 36 . 28 + 36 . 82 + 64 . 69 + 64 . 41.
b) 13,5 . 5,8 – 8,3 . 4,2 – 5,8 . 8,3 + 4,2 . 13,5 .
c) 4,8 . 13,3 + 4,8 . 6,7 + 5,2 . 13,3 + 5,2 . 6,7 .
d) 7,8 . 55,1 + 92,2 . 55,1 – 7,8 . 5,1 – 92,2 . 5,1
e)170 . 22,89 – 128,9 . 17 f)3,71 . 34 + 66 .3,71 .
g)85 . 12,7 + 5 . 3 . 12,7 h)47 . 9,9 + 53 . 9,9
i)52 . 143 – 52 . 39 – 8 . 26 k)13 . 49 + 38 . 49 – 25 . 49 + 49 . 74
Giúp nhanh nha, làm được trên 7 câu nha chớ k tui báo cáo á

Comments ( 2 )

  1. Bài 1
    a)5x.(x-2y)+2.(2y-x)
    =5x.(x-2y)-2.(x-2y)
    =(x-2y).(5x-2)
    b)5x (x-11 ) -10y(x – 11 )
    =(x-11).(5x-10y)
    =5.(x-11).(x-2y)
    j)a^2b^4+a^3b-abc
    =ab.(ab^2+a^2-c)
    l)7x.(y-4)^2-(4-y)^3
    =7x.(4-y)^2-(4-y)^3
    =(4-y)^2.(7x-4-y)
    =(16-8y+y^2).(7x-4-y)
    k)– x^2y^2z – 6x^3y – 8x^4z^2 – 9x^5y^5z^5
    =-x^2.(y^2z+6xy+8x^2z^2-9x^3y^5z^5)
    m)x^2-x+1+7x.(x^2-x+1)
    =(x^2-x+1)+7x.(x^2-x+1)
    =(x^2-x+1).(1+7x)
    f)x.(x+y)-(2x+2y)
    =x.(x+y)-2.(x+y)
    =(x+y).(x-2)
    g)2x.(x+y)-10x-10y
    =2x.(x+y)-(10x+10y)
    =2x.(x+y)-10.(x+y)
    =(x+y).(2x-10)
    =2.(x+y).(x-5)
    n)5x^5 (y^3+3y – 13 ) – 4y (y^3+3y – 13 ) – 2x.(y^3+3y – 13 )
    =(y^3+3y-13).(5x^5-4y-2x)
    Bài 2.
    a)36.28+36.82+64.69+64.41
    =36.(28+82)+64.(69+41)
    =36.110+64.110
    =110.(36+64)
    =110.100
    =11000
    b)13,5 . 5,8 – 8,3 . 4,2 – 5,8 . 8,3 + 4,2 . 13,5
    =13,5.(5,8+4,2)-8,3.(4,2+5,8)
    =13,5.10-8,3.10
    =10.(13,5-8,3)
    =10.5,2
    =52
    c) 4,8 . 13,3 + 4,8 . 6,7 + 5,2 . 13,3 + 5,2 . 6,7
    =4,8.(13,3+6,7)+5,2.(13,3+67)
    =(13,3+6,7).(4,8+5,2)
    =20.10
    =200
    d)7,8 . 55,1 + 92,2 . 55,1 – 7,8 . 5,1 – 92,2 . 5,1
    =55,1.(7,8+92,2)-5,1.(7,8+92,2)
    =(7,8+92,2).(55,1-5,1)
    =100.50
    =5000
    e)170 . 22,89 – 128,9 . 17
    =17.10.22,89-128,9.17
    =17.228,9-128,9,17
    =17.(228,9-128,9)
    =17.100
    =1700
    f)3,71.34+66.37,1
    =37,1.(34+66)
    =37,1.100
    =3710
    g)85 . 12,7 + 5 . 3 . 12,7
    =85.12,7+15.12,7
    =12,7.(85+15)
    =12,7.100
    =1270
    h)47 . 9,9 + 53 . 9,9
    =9,9.(47+53)
    =9,9.100
    =990
    i)52 . 143 – 52 . 39 – 8 . 26
    =52.143-52.39-4.2.26
    =52.143-52.29-4.52
    =52.(143-39-4)
    =52.100
    =5200
    k)13 . 49 + 38 . 49 – 25 . 49 + 49 . 74
    =49.(13+38-25+74)
    =49.100
    =4900
    $#chúc tus học tốt!!$
    #La 
     

  2. Bài 1: phân tích đa thức thành nhân tử
    a) 5x (x – 2y) + 2 ( 2y – x )
    = 5x (x – 2y) – 2 ( x – 2y )
    = (x – 2y)(5x – 2)
    b) 5x (x – 11 ) – 10y(x – 11 )
    = (x – 11)(5x – 10y)
    = 5(x – 2y)(x – 11)
    j) a²b^4 + a³b – abc
    = ab(ab³ + a² – c)
    l) 7x(y– 4)² – (4 – y)³
    = 7x(y – 4)² + (y – 4)³
    = (y – 4)²(7x + y – 4)
    k) – x²y²z – 6x³y – 8x^4z³ – 9x^5y^5z^5
    = – x²(y²z + 6xy + 8x²z³ + 9x³y^5z^5)
    f) x(x+y) – (2x+2y)
    = x(x + y) – 2(x + y)
    = (x + y)(x – 2)
    g) 2x(x+y) – 10x – 10y
    = 2x(x + y) – 10(x + y)
    = (x + y)(2x – 10)
    = 2(x – 5)(x + y)
    n) 5x^5 (y³+3y – 13 ) – 4y (y³+3y – 13 ) – 2x(y³+3y – 13)
    = (y³ + 3y – 13(5x^5 – 4y – 2x
    m) x² – x + 1 + 7x (x² – x + 1)
    = (x² – x + 1)(1 + 7x)

    Bài 2: Tính nhanh
    a) 36 . 28 + 36 . 82 + 64 . 69 + 64 . 41
    = (36 . 28 + 36 . 82) + (64 . 69 + 64 . 41)
    = 36(28 + 82) + 64(69 + 41)
    = 36 . 110 + 64 . 110
    = 110(36 + 64)
    = 110 . 100 = 11000
    b) 13,5 . 5,8 – 8,3 . 4,2 – 5,8 . 8,3 + 4,2 . 13,5 
    = (13,5 . 5,8 
    + 4,2 . 13,5) – (8,3 . 4,2 + 5,8 . 8,3)
    = 13,5(5,8 + 4,2) – 8,3(4,2 + 5,8)
    = 13,5 . 10 – 8,3 . 10
    = 10(13,5 – 8,3)
    = 10 . 5,2 = 52
    c) 4,8 . 13,3 + 4,8 . 6,7 + 5,2 . 13,3 + 5,2 . 6,7
    = (4,8 . 13,3 + 4,8 . 6,7) + (5,2 . 13,3 + 5,2 . 6,7)
    = 4,8(13,3 + 6,7) + 5,2(13,3 + 6,7)
    = 4,8 . 20 + 5,2 . 20
    = 20(4,8 + 5,2)
    = 20 . 10 = 200
    d) 7,8 . 55,1 + 92,2 . 55,1 – 7,8 . 5,1 – 92,2 . 5,1
    = (7,8 . 55,1 
    – 7,8 . 5,1) + (92,2 . 55,1  – 92,2 . 5,1)

    = 7,8 . 50 + 92,2 . 50
    = 50(7,8 + 92,2)
    = 50 . 100 = 5000
    e) 170 . 22,89 – 128,9 . 17
    = 17 . 10 . 22,89 – 128,9 . 17
    = 17(228,9 – 128,9)
    = 17 . 100 = 1700
    f) 3,71 . 34 + 66 .3,71
    = 3,71(34 + 66)
    = 3,71 . 100
    = 371
    g) 85 . 12,7 + 5 . 3 . 12,7
    = 12,7(85 + 15)
    = 12,7 . 100
    = 1270
    h) 47 . 9,9 + 53 . 9,9
    = 9,9(47 + 53)
    = 9,9 . 100 = 990
    i) 52 . 143 – 52 . 39 – 8 . 26
    = 52 . 143 – 52 . 39 – 52 . 4
    = 52(143 – 39 – 4)
    = 52 . 100 = 5200
    k) 13 . 49 + 38 . 49 – 25 . 49 + 49 . 74
    = 49(13 + 38 – 25 + 74)
    = 49 . 100 = 4900

    Good luck !!!
    @ Sun

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