Решите пж и сделайте проверку7* Х +

1) 7х + 9 - 5у = 13 8) 55 - ( х - 15) = 30 10) (580 - х) : 4 = 100
7х - 5у = 4 55 - х + 15 = 30 580 - х = 400
не могу решить 70 - х = 30 х = 180
2) 10х +3 - х = 12 х = 40 400 :4 = 100
9х + 3 = 12 55 - 25 = 30
9х = 9 9) (1167 + 34567) - х = 11245
х = 1 35734 - х = 11245
10 1 + 3 - 1 = 12 х =35734 - 11245
9 + 3 = 12 х = 24489
3) (х + 15) - 18 = 17 35734 - 24489 = 11245
х + 15 = 35
х = 20
35 - 18 = 17
4)(24 + х ) - 21 = 10
24 + х = 31
х = 7
31 - 21 = 10
5) 900 - 5х = 800
-5х = -100
х = 20
900 - 5 20 = 800
900 - 100 = 800
6)( (х - 2756 )- 8073 = 1844
х - 2756 = 9917
х = 12673
(12673 - 2756 ) - 8073 = 1844
9917 - 8073 = 1844
7)( х - 35)+ 12 = 32
х - 35 = 20
х = 55
20 + 12 =32