BA - B = - 4
B * ( A - 1 ) = - 4
B = - 4 / ( A - 1 )
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BA^2 - B = 9
B * ( A^2 - 1 ) = 9
B = 9 / ( A^2 - 1 )
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B = B
- 4 / ( A - 1 ) = 9 / ( A^2 - 1 )
- 4 * ( A + 1 ) = 9
- 4A - 4 = 9
- 4A = 5
A = ( - 5/4) = ( - 1,25 )
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B = - 4 / ( - 1,25 - 1 )
B = - 4 / - 2,25
B = 4/1 : 9/4 = 16/9
B = 1 целая 7/9
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ОТВЕТ: А = ( - 1 целая 1/4 ) ; В = 1 целая 7/9