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: Bài 5: Rút gọn các biểu thức sau: a) ????.(2????^2−3)−????^2.(5????+1)+????^2 b) 3????.(????−2)−5????.(1−????)−8.(????^2−3) c) ????=(3.????^(????+1)−2.????^????).

Toán Lớp 8: Bài 5: Rút gọn các biểu thức sau: a) ????.(2????^2−3)−????^2.(5????+1)+????^2 b) 3????.(????−2)−5????.(1−????)−8.(????^2−3) c) ????=(3.????^(????+1)−2.????^????).4????^2 d) ????=2????^????.(3.????^(????+1)−1)−3.????^(????+1).(2.????^????−1)

Comments ( 1 )

  1. Giải đáp+Lời giải và giải thích chi tiết:
    a) x(2x^2-3)-x^2(5x+1)+x^2
    =2x^3-3x-5x^3-x^2+x^2
    =(2x^3-5x^3)+(x^2-x^2)-3x
    =-3x^3-3x
    b) 3x(x-2)-5x(1-x)-8(x^2-3)
    =3x^2-6x-5x+5x^2-8x^2+24
    =(3x^2+5x^2-8x^2)-(6x+5x)+24
    =-11x+24
    c) (3x^{n-1}-2x^n).4x^2
    =12x^{2+n-1}-8x^{2+n}
    =12x^{n+1}-8x^{2+n}
    d) 2x^{n}(3x^{n+1}-1)-3x^{n+1}.(2x^n-1)
    =6x^{n+n+1}-2x^n-6x^{n+1+n}+3x^{n+1}
    =6x^{2n+1}-2x^n-6x^{2n+1}+3x^{n+1}
    =(6x^{2n+1}-6x^{2n+1})+3x^{n+1}-2x^n
    =3x^{n+1}-2x^n

Leave a reply

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