1)х+46=75
х=75-46
х=29
_____________________
2)78+3х-25=104
3х+53=104
3х=104-53
3х=51
х=51/3
х=17
_________________________
3)54+х+32=96
х+86=96
х=96-86
х=10
______________________________
х+3х+3х+29=155
7х=155-29
7х=126
х=126/7
х=18
_______________________