Как решить

475 - (x-671) = 325

403 - (634-a) = 366

987 - (x+364) = 519

1) 475 - (x-671) = 325

x-671=475+325

x-671=800

x=800+671

x=1471

475 - (1471-671) = 325

2) 403 - (634-a) = 366

634-a=403-366

634-a=37

a=634-37

a=597

403 - (634-597) = 366

3) 987 - (x+364) = 519

x+364=987-519

x+364=468

x=468-364

x=104

987 - (104+364) = 519

475 - (х-651) = 325

х-651=475-325

*-651=150

*=651+150

*=801

403 - (634-а) = 366

634-а=403-366

634-а=37

а=634-37

а=597

987 - (*+364) = 519

987-519=468

468+364=832

*=832