a. 5x – 16 = 40 + x b. 4x – 10 = 15 – x c. -12 + x = 5x – 20 d. 7x – 4 = 20 + 3x e. 5x – 7 = – 21 – 2x f. x + 15 = 7 – 6x g. 17 – x = 7 – 6x

a. 5x – 16 = 40 + x
b. 4x – 10 = 15 – x
c. -12 + x = 5x – 20
d. 7x – 4 = 20 + 3x
e. 5x – 7 = – 21 – 2x
f. x + 15 = 7 – 6x
g. 17 – x = 7 – 6x

0 bình luận về “a. 5x – 16 = 40 + x b. 4x – 10 = 15 – x c. -12 + x = 5x – 20 d. 7x – 4 = 20 + 3x e. 5x – 7 = – 21 – 2x f. x + 15 = 7 – 6x g. 17 – x = 7 – 6x”

  1. a. 5x – 16 = 40 + x

    \(\Leftrightarrow 5x – x = 40 + 16\)

    \(\Leftrightarrow 4x = 56\)

    \(\Leftrightarrow x = 14\)

    b. 4x – 10 = 15 – x

    \(\Leftrightarrow 4x + x = 15 + 10\)

    \(\Leftrightarrow 5x = 25\)

    \(\Leftrightarrow x = 5\)

    c. -12 + x = 5x – 20

    \(\Leftrightarrow x – 5x = -20+12\)

    \(\Leftrightarrow -4x=-8\)

    \(\Leftrightarrow x=2\)

    d. 7x – 4 = 20 + 3x

    \(\Leftrightarrow 7x – 3x = 20 + 4\)

    \(\Leftrightarrow 4x = 24\)

    \(\Leftrightarrow x = 6\)

    e. 5x – 7 = – 21 – 2x

    \(\Leftrightarrow 5x + 2x = -21 + 7\)

    \(\Leftrightarrow 7x = -14\)

    \(\Leftrightarrow x=-2\)

    f. x + 15 = 7 – 6x

    \(\Leftrightarrow x + 6x = 7 – 15\)

    \(\Leftrightarrow 7x = -8\)

    \(\Leftrightarrow x = -\dfrac{8}{7}\)

    g. 17 – x = 7 – 6x

    \(\Leftrightarrow -x + 6x = 7 – 17\)

    \(\Leftrightarrow 5x = -10\)

    \(\Leftrightarrow x = -2\)

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