<span>2,85*0,5+4,6*0,5-3,05=0,675
1)2,85*0,5=1,425
2)4,6*0,5=2,3
3)1,425+2,3=3,725
4)3,725-3,05=0,675</span>
428000-(х+28234)=243146
Х+28234=428000-243146
Х+28234=184854
Х=184854-28234
Х=156620
7x- (3+2x) = x+9
7x - 3 - 2x = x + 9
7x - 2x - x = 9 + 3
4x = 12
x = 12 / 4
x = 3