Register Now

Login

Lost Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

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

Toán Lớp 8: a) 4x.(6x-8)+(3x-4).(5x-2) b) $(7x-4)^{2}$ – $(x+7)^{2}$ c) $64x^{2}$ – $125y^{3}$

Home/ Toán Lớp 8: a) 4x.(6x-8)+(3x-4).(5x-2) b) $(7x-4)^{2}$ – $(x+7)^{2}$ c) $64x^{2}$ – $125y^{3}$

Toán Lớp 8: a) 4x.(6x-8)+(3x-4).(5x-2) b) $(7x-4)^{2}$ – $(x+7)^{2}$ c) $64x^{2}$ – $125y^{3}$

Tháng Năm 29, 2022 Toán học 2 Comments 0 views

Toán Lớp 8: a) 4x.(6x-8)+(3x-4).(5x-2)
b) $(7x-4)^{2}$ – $(x+7)^{2}$
c) $64x^{2}$ – $125y^{3}$

Comments ( 2 )

  1. tuyethutanhthu
    tuyethutanhthu
    29 Tháng Năm, 2022 at 4:14 sáng
    Reply
    a) 4x(6x-8)+(3x-4)(5x-2)
    = 8x(3x-4)+(3x-4)(5x-2)
    = (8x+5x-2)(3x-4)
    = (13x-2)(3x-4)
    b) (7x-4)^2-(x+7)^2
    = (7x-4-x-7)(7x-4+x+7)
    = (6x-11)(8x+3)
    c) 64x^3-125y^3
    = (4x)^3-(5y)^3
    = (4x-5y)(16x^2+20xy+25y^2)

  2. dananhnhu2k4
    dananhnhu2k4
    29 Tháng Năm, 2022 at 4:14 sáng
    Reply
    a) 4x( 6x – 8 ) + ( 3x – 4 ) ( 5x – 2 )
    = 24x² – 32x + (15x² – 6x – 20x + 8)
    = 24x²- 32x + 15x² – 6x – 20x + 8
    = 24x² + 15x² + ( -32x – 6x – 20x ) + 8
    = 39x² – 58x + 8
    b) ( 7x – 4)² – ( 3x + 7)²
    = (7x)²- 2.7x.4 + 4² – [(3x)² + 2.3x.7 + 7²]
    = (7x)² – 2.7x.4 + 4² – (3x)² – 2.3x.7 – 7²
    = 49x² – 56x + 16 – 9x² – 42x – 49
    = 49x² – 9x² + ( -56x – 42x ) + ( 16 – 49 )
    = 40x² – 98x – 33
    c) 64x³ – 125y³
    = (4x)³ – ( 5y )³
    = (4x – 5y) [(4x)² + 4x . 5y + (5y)²]
    = (4x – 5y) (16x² + 20xy + 25y²)

Leave a reply

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

Việt Lan

About Việt Lan