1) 5500-x = 3939
x = 5500-3939
x = 1561
Пр.: 5500 - 1561 = 3939
2) m : 9 = 81810
m = 81810*9
m = 736290
Пр.: 736290 : 9 = 81810
4^2x+1= 128^x+5
2^4x+2= 2^7x+35
4x+2=7x+35
-3x=33
x= -11
6x=-12=x=-2
2x=12=x=6
x=-1
x=3
3a+21-3a=21
-4a-16+4a=-16