-1+2+4-5+7+6-8-9+12

解

- 1 + 2 + 4 - 5 + 7 + 6 - 8 - 9 + 12

8

解答ステップ

- 1 + 2 + 4 - 5 + 7 + 6 - 8 - 9 + 12

演算のPEMDAS順に従う

足して割る (左から右)

- 1 + 2 = 1

= 1 + 4 - 5 + 7 + 6 - 8 - 9 + 12

1 + 4 = 5

= 5 - 5 + 7 + 6 - 8 - 9 + 12

5 - 5 = 0

= 0 + 7 + 6 - 8 - 9 + 12

0 + 7 = 7

= 7 + 6 - 8 - 9 + 12

7 + 6 = 13

= 13 - 8 - 9 + 12

13 - 8 = 5

= 5 - 9 + 12

5 - 9 = - 4

= - 4 + 12

- 4 + 12 = 8

= 8

数直線

= 8