90 000 - 705×83 = 31 485
80 100 - 603×79 = 32 463
1)х+3,82=7
х=7-3,82
х=3,18
2)28,9-х=5,347
х=28,9-5,347
х=23,553
3)х-23,427=6,873
х=6,873+23,427
х=30,3
4)(81-х)+27,8=39,156
81-х+27,8=39,156
108,8-х=39,156
х=108,8-39,156
х=69,644
72-56÷(5+2)+3*8=72-56÷7+3*8=72-8+24=88