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) (x-3)(x+3) + x mũ 2 .(x+1)(x-1) b) x mũ 2 – 2x +1=0

Home/ Toán Lớp 8: a) (x-3)(x+3) + x mũ 2 .(x+1)(x-1) b) x mũ 2 – 2x +1=0

Toán Lớp 8: a) (x-3)(x+3) + x mũ 2 .(x+1)(x-1) b) x mũ 2 – 2x +1=0

Tháng Tám 29, 2022 Toán học 2 Comments 0 views

Toán Lớp 8: a) (x-3)(x+3) + x mũ 2 .(x+1)(x-1)
b) x mũ 2 – 2x +1=0

Comments ( 2 )

  1. tuyethutanhthu
    tuyethutanhthu
    29 Tháng Tám, 2022 at 12:49 sáng
    Reply
    $a)   (x-3)(x+3) + x^2 .(x+1)(x-1)^{}$ 

    $=(x^2-9)+x^2(x^2-1)^{}$ 

    $=x^2-9+x^4-x^{2}$ 

    $=(x^2)^2-3^{2}$ 

    $=(x^2-3)(x^2+3)^{}$ 

    $b)  x^2 – 2x + 1 = 0^{}$ 

    $⇔(x-1)^2 = 0^{}$ 

    $⇔ x – 1 = 0^{}$ 

    $⇔ x = 1^{}$ 

  2. dananhnhu2k4
    dananhnhu2k4
    29 Tháng Tám, 2022 at 12:49 sáng
    Reply
    a):
    (x-3)(x+3) + x^2 * (x+1)(x-1)
    = x^2−3^2+x^2(x+1)(x−1)
    = x^2−3^2+(x^3+x^2)(x−1)
    = x^2−3^2+x^4−x^3+x^3−x^2
    = x^2−9+x^4−x^3+x^3−x^2
    = (x^2−x^2)−9+x^4+(−x^3+x^3)
    = −9+x^4
    = x^4−9
    b):
    x^2 – 2x +1=0
    ⇒ x^2−2(x)(1)+1^2=0
    ⇒ (x−1)^2=0
    ⇒ x−1=0
    ⇒ x = 0 + 1
    → x = 1

Leave a reply

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

Ngọc

About Ngọc