34х+66х=100х
при х=8, 100*8=800
54а-39а=15а
при а=26, 15*26=390
18m-5m+7m=20m
при m=394, 20*394=7880
19z-12z+33z-192=40z-192
при z=82, 40*82-192=3280-192=3088
2*(x+(x+5))=54
x=11 (см) Ширина
11+5=16 см Длина
S=11*16
S=176 кв.см
65700 рублей по-моему
50х365=18250
40х365=14600
18250+14600=32850
32850х2=65700
а) <span>5d=-85,6-3d</span>
8d+85.6=0
d=-85.6/8
d=-10.7
б) (5b)/6-(5b+1)/9=(1b)/2+1//3
(5//6)b-(5*b/9+1/9)-b/2-(1//3)=0
(5//6)b-((5//9)b+(1//9))-b/2-(1//3)=0
(5//18)b-(1//9)-b/2-(1//3)=0
-(2//9)b-(1//9)-(1//3)=0
-(2//9)b-(4//9)=0
b=(4//9)/(-(2//9))
b=-2
// - черта дроби