与えられた21個の方程式をそれぞれ解き、$x$ の値を求める問題です。

1. 問題の内容

与えられた21個の方程式をそれぞれ解き、$x$ の値を求める問題です。

2. 解き方の手順

(4) $2x - 5 = 3$

$2x = 3 + 5$

$2x = 8$

$x = 4$

(5) $4x = 7x + 15$

$4x - 7x = 15$

$-3x = 15$

$x = -5$

(6) $8x - 10 = x + 4$

$8x - x = 4 + 10$

$7x = 14$

$x = 2$

(7) $5x + 2 = 5 + 6x$

$5x - 6x = 5 - 2$

$-x = 3$

$x = -3$

(8) $6x - 1 = 8x - 9$

$6x - 8x = -9 + 1$

$-2x = -8$

$x = 4$

(9) $x + 2 = -7x + 18$

$x + 7x = 18 - 2$

$8x = 16$

$x = 2$

(10) $-4x + 7 = 5x - 2$

$-4x - 5x = -2 - 7$

$-9x = -9$

$x = 1$

(11) $-6x - 1 = x + 6$

$-6x - x = 6 + 1$

$-7x = 7$

$x = -1$

(12) $6 - 3x = 9x + 6$

$-3x - 9x = 6 - 6$

$-12x = 0$

$x = 0$

(13) $4 + x = 3x - 2$

$x - 3x = -2 - 4$

$-2x = -6$

$x = 3$

(14) $9 - 2x = 5 - 6x$

$-2x + 6x = 5 - 9$

$4x = -4$

$x = -1$

(15) $12 - 8x = 3x - 10$

$-8x - 3x = -10 - 12$

$-11x = -22$

$x = 2$

(16) $5x - 4 = 3x - 3$

$5x - 3x = -3 + 4$

$2x = 1$

$x = \frac{1}{2}$

(17) $-3x - 12 = 7x + 3$

$-3x - 7x = 3 + 12$

$-10x = 15$

$x = -\frac{3}{2}$

(18) $5x - 11 = 5 - 7x$

$5x + 7x = 5 + 11$

$12x = 16$

$x = \frac{4}{3}$

(19) $5(x - 4) = x$

$5x - 20 = x$

$5x - x = 20$

$4x = 20$

$x = 5$

(20) $8 - 7x = -6$

$-7x = -6 - 8$

$-7x = -14$

$x = 2$

(21) $-1 - 3x = 8$

$-3x = 8 + 1$

$-3x = 9$

$x = -3$

3. 最終的な答え

(4) $x = 4$

(5) $x = -5$

(6) $x = 2$

(7) $x = -3$

(8) $x = 4$

(9) $x = 2$

(10) $x = 1$

(11) $x = -1$

(12) $x = 0$

(13) $x = 3$

(14) $x = -1$

(15) $x = 2$

(16) $x = \frac{1}{2}$

(17) $x = -\frac{3}{2}$

(18) $x = \frac{4}{3}$

(19) $x = 5$

(20) $x = 2$

(21) $x = -3$