Ответ:

1) х*7=330-274

х*7=56

х=56:7

х=8

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8*7=56

56=56

2) (502-2)*а=1000

500*а=1000

а=1000:500

а=2

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500*2=1000

1000=1000

3) х+30*5=365

х+150=365

х=365-150

х=215

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215+150=365

365=365

4)х:4=100-22

х:4=78

х=78*4

х=312

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312:4=78

78=78

1)х*7 = 330-274

7х  =  330  −  274

7х = 56

х = 8

8*7 = 330-274

56 = 56

2)(502 - 2) * а = 1000

500 * а = 1000

а = 1000 : 500

а = 2

(502 - 2) * 2 = 1000

500*2 =1000

1000 = 1000

3)х+30*5=365

х + 30 = 365 : 5

х + 30 = 73

х = 73 - 30

х = 43

43 + 30 * 5 = 365

365 = 365

4) х:4=100-22

х:4=78

х=78*4

х=312

312 : 4 = 100-22

78 = 78