12х+14х+4.2=12;(9.8-х):9=0.7

Question

12х+14х+4.2=12;(9.8-х):9=0.7

Answer 1

12х+14х+4.2=12

26х+4.2=12

26х=12-4.2

26х=7.8

х=0.3

Проверка:

12*0.3+14*0.3+4.2=12

1)12*0.3=3.6

2)14*0.3=4.2

3)3.6+4.2=7.8

4)7.8+4.2=12

Ответ:0.3

(9.8-х):9=0.7

9.8-х=0.7*9

9.8-х=6.3

х=9.8-6.3

х=3.5

Проверка:

(9.8-3.5):9=0.7

1)9.8-3.5=6.3

2)6.3:9=0.7

Отрвет:х=3.5