=5-166=-161
=39-4(52/54)=34(1/27)
=48+89-10,5=126,5
3478
+2295
6693
---------
12466
1/6:(1/4x-1/3)-3/8=1/40
1/6:(1/4х-1/3)=1/40+3/8
1/6:(1/4х-1/3)= 2/5
2/5*(1/4х-1/3)= 1/6
1/10х-2/15=1/6
1/10х= 1/6+2/15
1/10х= 3/10
Х= 3/10:1/10
Х=3/10*10
Х= 3
160/20=8 см длина
2*(8+20) =56 см - периметр
1) 5.9x+2.9x=27.28
8.8x=27.28 | : 8.8
x= 3.1
3) 3.5x+5.1x=24.94
8.6x=24.94 | : 8.6
x=2.9
5) (12-x)*6.5=23.4
78-6.5x=23.4
-6.5x=23.4-78
-6.5x= -54.6 | : -6.5
x=8.4
7) 153 + 0.625y=215,5
0.625y=215-153
0.625y=62 | : 0.625
y=99,2