Реши уравнения. ГДЗ. Математика. 5 класс. Дорофеев. Часть 1. Гл.2 § 4 п. 4 Вопр. 762

Решение уравнения:
1) 780 : (x – 24) + 25 = 90
780 : (x – 24) = 90 – 25                                                        
x – 24 = 780 : 65                                                                                                                             
x – 24 = 12
x = 12 + 24
x = 36
2) (31 – y : 350) • 8 = 200
31 – y : 350 = 200 : 8
y : 350 = 31 – 25
y : 350 = 6
y = 350 • 6
y = 2100
3) (2x + x + 9 + 8x) : 4 – 26 = 45
(11x + 9) : 4 = 45 + 26
11x + 9 = 71 • 4
11x = 284 – 9
x = 275 : 11
x = 25
4) 52 – (3y + 4 + y + 3y) : 37 = 50 
(7y + 4) : 37 = 52 – 50
7y + 4 = 37 • 2
7y = 74 – 4
11x = 275
y = 70 : 7
y = 10