(х-2,5)*4 1/5=6,3
х-25/10=63/10:21/5
х-25/10=63/10*10/21
х-25/10=3
х=3+25/10
х=30/10+25/10
х=55/10=5 1/2
3,5*(х+2 1/4)=14
х+9/4=14:35/10
х+9/4=14*10/35
х+9/4=20/5
х+9/4=4
х=4-9/4
х=16/4-9/4
х=7/4=1 3/4
(1 3/4+х):1,9=2,5
7/4+х=25/10*19/10
7/4+х=475/100
х=475/100-7/4
х=475/100-175/100
х=300/100=3
(7,1-х):3,6=1 1/2
71/10-х=3/2*36/10
71/10-х=54/10
х=71/10-54/10
х=17/10=1 7/10