与えられた数式の中の空欄を埋める問題です。 (31) $4 = 2 \times \Box - 6$ (32) $4 = 1 + 12 \div \Box$ (33) $1 = \Box - 2 \times 2$ (34) $6 = 9 \div 3 + \Box$ (35) $13 = \Box \times 8 - 3$ (36) $3 = 17 - \Box \times 7$ (37) $13 = 4 + 36 \div \Box$ (38) $20 = \Box \times 9 - 7$ (39) $7 = 18 \div 3 + \Box$ (40) $6 = \Box + 8 \div 2$

1. 問題の内容

与えられた数式の中の空欄を埋める問題です。

(31) $4 = 2 \times \Box - 6$

(32) $4 = 1 + 12 \div \Box$

(33) $1 = \Box - 2 \times 2$

(34) $6 = 9 \div 3 + \Box$

(35) $13 = \Box \times 8 - 3$

(36) $3 = 17 - \Box \times 7$

(37) $13 = 4 + 36 \div \Box$

(38) $20 = \Box \times 9 - 7$

(39) $7 = 18 \div 3 + \Box$

(40) $6 = \Box + 8 \div 2$

2. 解き方の手順

各数式について、空欄をxとおいて解きます。

(31) $4 = 2 \times x - 6$

$2x = 4 + 6 = 10$

$x = 5$

(32) $4 = 1 + 12 \div x$

$12 \div x = 4 - 1 = 3$

$x = 12 \div 3 = 4$

(33) $1 = x - 2 \times 2$

$1 = x - 4$

$x = 1 + 4 = 5$

(34) $6 = 9 \div 3 + x$

$6 = 3 + x$

$x = 6 - 3 = 3$

(35) $13 = x \times 8 - 3$

$8x = 13 + 3 = 16$

$x = 16 \div 8 = 2$

(36) $3 = 17 - x \times 7$

$7x = 17 - 3 = 14$

$x = 14 \div 7 = 2$

(37) $13 = 4 + 36 \div x$

$36 \div x = 13 - 4 = 9$

$x = 36 \div 9 = 4$

(38) $20 = x \times 9 - 7$

$9x = 20 + 7 = 27$

$x = 27 \div 9 = 3$

(39) $7 = 18 \div 3 + x$

$7 = 6 + x$

$x = 7 - 6 = 1$

(40) $6 = x + 8 \div 2$

$6 = x + 4$

$x = 6 - 4 = 2$

3. 最終的な答え

(31) 5

(32) 4

(33) 5

(34) 3

(35) 2

(36) 2

(37) 4

(38) 3

(39) 1

(40) 2