50*(x-173)=2500
1748:x+77=123

50*(x-173)=2500

50х-8650=2500

50х=2500+8650

50х=11150

х=11150/50

х=223

Проверяем: 50*(223-173)=2500

                       50*50=2500

                        2500=2500

1748:x+77=123

1748/х=123-77

1748/х=46

х=1748/46

х=38

Проверяем: 1748/38+77=123

                      46+77=123

                        123=123

1) 50*(х-173) = 2500

х-173=2500:50

х-173 = 50

х = 173+50

х= 223

2) 1748:х + 77 = 123

1748 :х = 123 - 77

1748:х = 46

х=1748 : 46

х=38