When solving the equation x2 – 8x – 7 = 0 by completing the square, which equation is a step in the process?

Question

When solving the equation x2 – 8x – 7 = 0 by completing the square, which equation
is a step in the process?

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Gerda 3 weeks 2021-08-23T23:21:23+00:00 1 Answers 1 views 0

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    0
    2021-08-23T23:22:37+00:00

    Answer:

    Lets Solve

     \\  \rm \longmapsto \:  {x}^{2}  - 8x - 7 = 0 \\  \\  \rm \longmapsto \:  {x}^{2}  - 8 {}^{}x = 7 \\  \\  \rm \longmapsto \: 4( {x}^{2}  - 8x) = 4 \times 7 \\  \\  \rm \longmapsto \:  {4x}^{2}  - 32x = 28 \\  \\  \rm \longmapsto \:  {(2x)}^{2}  - 2 \times 2x \times 8 = 28 \\  \\  \rm \longmapsto \: (2x) {}^{2}  - 2 \times 2x \times 8 +  {8}^{2}  = 28 +  {8}^{2}  \\  \\  \rm \longmapsto \:  {(2x - 8)}^{2}  = 64 + 28 \\  \\  \rm \longmapsto \:  {(2x - 8)}^{2}  = 92 \\  \\  \rm \longmapsto \: 2x - 8 =  \underline{ + }9.3 \\ \\  \rm \longmapsto \:2x =  8 + 9.3  \: or \: 8 - 9.3 \\ \\  \rm \longmapsto \:2x = 17.3 \:or \:  - 1.3 \\ \\  \rm \longmapsto \:2x = 17.3 \\ \\  \rm \longmapsto \:x =  \frac{17.3}{2}  \\ \\  \rm \longmapsto x = \:8.6

    • Ignore negative value

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Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )