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

Toán Lớp 8: (x + 3)(x2 – 3x + 9) – x(5+ x2) = 52 4x(5 – x) + ( x – 1)(4x – 3 ) =3 2x(x + 2) – (2x + 3)(x – 1) = 4 4x(x – 5) – ( x – 1)

Home/ Toán Lớp 8: (x + 3)(x2 – 3x + 9) – x(5+ x2) = 52 4x(5 – x) + ( x – 1)(4x – 3 ) =3 2x(x + 2) – (2x + 3)(x – 1) = 4 4x(x – 5) – ( x – 1)

Toán Lớp 8: (x + 3)(x2 – 3x + 9) – x(5+ x2) = 52 4x(5 – x) + ( x – 1)(4x – 3 ) =3 2x(x + 2) – (2x + 3)(x – 1) = 4 4x(x – 5) – ( x – 1)

Tháng Bảy 26, 2022 Toán học 2 Comments 0 views

Toán Lớp 8: (x + 3)(x2 – 3x + 9) – x(5+ x2) = 52
4x(5 – x) + ( x – 1)(4x – 3 ) =3
2x(x + 2) – (2x + 3)(x – 1) = 4
4x(x – 5) – ( x – 1)(4x – 3 ) = 3

Comments ( 2 )

  1. quynhthanhnhu
    quynhthanhnhu
    26 Tháng Bảy, 2022 at 9:02 sáng
    Reply
    Giải đáp:
     
    Lời giải và giải thích chi tiết:
     (x + 3)(x^2 – 3x + 9) – x(5+ x^2) = 52
    <=>x^3+27−x(5+x^2)=52
    <=>x^3+27−(5x+x^3)=52
    <=>x^3+27−5x−x^3=52
    <=>27−5x=52
    <=>−5x=52−27
    <=>−5x=25
    <=>x=\frac{25}{-5}=-5
    Vậy x=-5
     
    4x(5 – x) + ( x – 1)(4x–3 )=3
    <=>20x−4x^2+4x^2−7x+3=3
    <=>20x−7x+3=3
    <=>13x+3=3
    <=>13x=3−3=0
    <=>x=0
    Vậy x=0
     
    2x(x + 2) – (2x + 3)(x – 1) = 4
    <=>2x^2+4x−(2x^2+x−3)=4
    <=>2x^2+4x−2x^2−x+3=4
    <=>4x−x+3=4
    <=>3x+3=4
    <=>3x=4−3=1
    <=>x=\frac{1}{3}
    Vậy x=\frac{1}{3}
     
    4x(x – 5) – ( x – 1)(4x – 3 ) = 3
    <=>4x^2−20x−(4x^2−7x+3)=3
    <=>4x^2−20x−4x^2+7x−3=3
    <=>−20x+7x−3=3
    <=>−13x−3=3
    <=>−13x=3+3=6
    <=>x=\frac{6}{-13}
    Vậy x=-\frac{6}{13}

  2. ngoclankhue
    ngoclankhue
    26 Tháng Bảy, 2022 at 9:02 sáng
    Reply
    Giải đáp:
    $\begin{array}{l}
    a)\left( {x + 3} \right)\left( {{x^2} – 3x + 9} \right) – x\left( {5 + {x^2}} \right) = 52\\
     \Leftrightarrow {x^3} + 27 – 5x – {x^3} = 52\\
     \Leftrightarrow 5x =  – 25\\
     \Leftrightarrow x =  – 5\\
    Vậy\,x =  – 5\\
    b)4x\left( {5 – x} \right) + \left( {x – 1} \right)\left( {4x – 3} \right) = 3\\
     \Leftrightarrow 20x – 4{x^2} + 4{x^2} – 3x – 4x + 3 = 3\\
     \Leftrightarrow 13x = 0\\
     \Leftrightarrow x = 0\\
    Vậy\,x = 0\\
    c)2x\left( {x + 2} \right) – \left( {2x + 3} \right)\left( {x – 1} \right) = 4\\
     \Leftrightarrow 2{x^2} + 4x – \left( {2{x^2} – 2x + 3x – 3} \right) = 4\\
     \Leftrightarrow 2{x^2} + 4x – 2{x^2} – x + 3 = 4\\
     \Leftrightarrow 3x = 1\\
     \Leftrightarrow x = \dfrac{1}{3}\\
    Vậy\,x = \dfrac{1}{3}\\
    d)4x\left( {x – 5} \right) – \left( {x – 1} \right)\left( {4x – 3} \right) = 3\\
     \Leftrightarrow 4{x^2} – 20x – 4{x^2} + 3x + 4x – 3 = 3\\
     \Leftrightarrow 13x =  – 6\\
     \Leftrightarrow x =  – \dfrac{6}{{13}}\\
    Vậy\,x =  – \dfrac{6}{{13}}
    \end{array}$

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

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