1) 12•4-76= 48-76= -28
2)19•4-48= 76-48= 28
3)-37-19•(-4)= -37 + 76= 39
4)8/5•3/4 + 11/8= 24/20+11/8= 48/40+55/40= 103/40= 2,575
5)29/30-5/18•6/25= 29/30- 30/450= 29/30 - 2/30=27/30= 0,9
6)16/21:12/35 -2= (16•35)/ (21•12) - 2 = (4•5)/(3•3) - 2= 20/9 - 2= 2/9
7)9(х-5)=-х
9х-45+х=0
10х=45
х=4,5
8)8+7х=9х+4
2х=4
х=2
9)4х+7=0
4х=-7
х= -7/4
х=-1,75
10)10х+9=7х
3х=-9
х=-3
11)-4-6х=4х-3
10х=-1
х=-0,1