100:(10+0) = 100:10 = 10
2*(15+25) = 2*40 = 80
30*2+13 = 60+13 = 73
21:7-3 = 3-3 = 0
Решение на фото. удачи!!!
0,64:0,8=0,8 1)18,36+0,8=18,44
8/27+m=17/27 1/3+n=5/12 m+1/4=2/3
m=17/-27-8/27 n=5/12-1/3 m=2/3-1/4
m=9/27 n=5/12-4/12 m=8/12-3/12
m=1/3 n=1/12 m=5/12
n+1/25=2/5 2/13+m=3/5
n=2/5-1/25 m=3/5-2/13
n=10/25-1/25 m=39/65-10/65
n=9/25 m=29/65