19*8-8у=64
152-8у=64
-8у=64-152
8у=152-64
8у=88
у=11
18х+109=181
18х=181-109
18х=72
х=72/18
х=4
105:х-7=8
105:х=15
15х=105
х=105/15
х=7
19*8-8у=64
152-8у=64
-8у=64-152
8у=152-64
8у=88
у=11
18х+109=181
18х=181-109
18х=72
х=72/18
х=4
105:х-7=8
105:х=15
15х=105
х=105/15
х=7