Question

уравнение (9+х)+13=43

Answer 1

первый способ:

(9 + х) + 13 = 43

9 + х = 43 - 13

9 + х = 30

х = 30 - 9

х = 21

второй способ:

(9 + х) + 13 = 43

9 + х + 13 = 43

х = 43 - 13 - 9

х = 21

Answer 2

9+х+13=43 , 22+х=43, х=43-22 , х=21