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

Toán Lớp 8: a) x4 + 1 – 2×2 b) x2 – y2 + 3y – 3x c) x2y + 2×2 – 9y – 18

Home/ Toán Lớp 8: a) x4 + 1 – 2×2 b) x2 – y2 + 3y – 3x c) x2y + 2×2 – 9y – 18

Toán Lớp 8: a) x4 + 1 – 2×2 b) x2 – y2 + 3y – 3x c) x2y + 2×2 – 9y – 18

Tháng Mười Một 6, 2022 Toán học 2 Comments 0 views

Toán Lớp 8: a) x4 + 1 – 2×2 b) x2 – y2 + 3y – 3x c) x2y + 2×2 – 9y – 18

d) x4 + 64 e) 4×2 – y2 + 4x + 1 f) a2( b – 1) + b2 (1 – b)
g) x3 – y3 – 3×2 + 3x – 1 h) 4×3 – 5×2 – 16x + 20 i) a6 + b6
k) x2 + 2x – 8

Comments ( 2 )

  1. quynhthanhnghi
    quynhthanhnghi
    6 Tháng Mười Một, 2022 at 3:54 chiều
    Reply
    Giải đáp:
     
    Lời giải và giải thích chi tiết:
     a, x^4 + 1 – 2x^2
    = (x^2)^2 – 2.x^2.1 +1^2
    = (x^2 – 1)^2
    b, x^2 – y^2 + 3y – 3x
    = (x-y)(x+y)-3(x-y)
    = (x-y)(x+y-3)
    c, x^2y +2x^2 – 9y – 18
    = x^2(y+2) – 9(y+2)
    = (x^2-9)(y+2)
    = (x-3)(x+3)(y+2)
    d, x^4 + 64
    = (x^2)^2 + 16x^2 + 64 – 16x^2
    = (x^2)^2 + 2.8.x^2 + 8^2 – 16x^2
    = (x^2 +8)^2 – (4x)^2
    = (x^2 + 8 – 4x) (x^2 + 8 + 4x)
    e, 4x^2 – y^2 + 4x + 1
    = (4x^2 + 4x + 1) – y^2
    = [(2x)^2 + 2.2x.1 + 1^2] – y^2
    = (2x + 1)^2 – y^2
    = (2x + 1 – y)(2x + 1 + y)
    f, a^2(b – 1)+b^2(1-b)
    =a^2(b-1)-b^2(b-1)
    =(a^2-b^2)(b-1)
    =(a-b)(a+b)(b-1)
    g,x^3-y^3-3x^2+3x-1
    = (x^3 – 3x^2 + 3x – 1) – y^3
    = (x^3 – 3.x^2.1 + 3.x.1^2 – 1^3) – y^3
    = (x-1)^3 – y^3
    = (x-1-y)[(x-1)^2+(x-1)y+y^2]
    = (x-y-1)(x^2-2x+1+xy-y+y^2]
    h, 4x^3 – 5x^2 – 16x + 20
    = x^2(4x-5)-4(4x-5)
    = (x^2-4)(4x-5)
    = (x-2)(x+2)(4x-5)
    i, a^6 + b^6
    = (a^2)^3 + (b^2)^3
    = (a^2 + b^2)[(a^2)^2 – a^2b^2 + (b^2)^2]
    = (a^2 + b^2)(a^4 – a^2b^2 + b^4)
    k, x^2 + 2x – 8
    = x^2 + 2x + 1 -9
    = (x+1)^2 – 3^2
    =(x+1-3)(x+1+3)
    =(x-2)(x+4)
    #Chii
    #Team: Extensive Knowledge 
    #Đã sửa

  2. maitrucloan
    maitrucloan
    6 Tháng Mười Một, 2022 at 3:53 chiều
    Reply
    a)x^4+1-2x^2
    =x^4+2x^3+x^2-2x^3-4x^2-2x+x^2+2x+1
    =x^2(x^2+2x+1)-2x(x^2+2x+1)+(x^2+2x+1)
    =(x^2-2x+1)(x^2+2x+1)
    =(x-1)^2(x+1)^2
    b)x^2-y^2+3y-3x
    =(x-y)(x+y)+3(y-x)
    =-(y-x)(x+y)+3(y-x)
    =(y-x)(-x-y+3)
    c)x^2y+2x^2-9y-18
    =x^2(y+2)-9(y+2)
    =(y+2)(x^2-9)
    =(y+2)(x-3)(x+3)
    d)x^4+64
    =x^4+4x^3+8x^2-4x^3-16x^2-32x+8x^2+32x+64
    =x^2(x^2+4x+8)-4x(x^2+4x+8)+8(x^2+4x+8)
    =(x^2-4x+8)(x^2+4x+8)
    e)4x^2-y^2+4x+1
    =4x^2+4x+1-y^2
    =(2x+1)^2-y^2
    =(2x+1-y)(2x+1+y)
    f)a^2(b-1)+b^2(1-b)
    =(b-1)(a^2-b^2)
    =(b-1)(a-b)(a+b)
    g)x^3-y^3-3x^2+3x-1
    =-y^3-xy^2+y^2-x^2y+2xy-y+xy^2+x^2y-xy+x^3-2x^2+x-y^2-xy+y-x^2+2x-1
    =-(y^3+xy^2-y^2+x^2y-2xy+y-xy^2-x^2y+xy-x^3+2x^2-x+y^2+xy-y+x^2-2x+1)
    =-[y(y^2+xy-y+x^2-2x+1)-x(y^2+xy-y+x^2-2x+1)+(y^2+xy-y+x^2-2x+1)]
    =-(y-x+1)(y^2+xy-y+x^2-2x+1)
    h)4x^3-5x^2-16x+20
    =x^2(4x-5)-4(4x-5)
    =(4x-5)(x^2-4)
    =(4x-5)(x-2)(x+2)
    i)a^6+b^6
    =(a^2)^3+(b^2)^3
    =(a^2+b^2)(a^4-a^2b^2+b^4)
    k)x^2+2x-8
    =(x+1)^2-9
    =(x+1-3)(x+1+3)
    =(x-2)(x+4)

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

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