Question

Сократите дробь

-5с^2+4с+1
__________
1-25с^2

Answer 1

- 5с² + 4с + 1 = ( - 5) *( c + 0,2 )( c - 1 ) = ( 1 - 5c )( c - 1 )
В = 16 + 20 = 36 ; √ D = 6
c1 = ( - 4 + 6 ) : ( - 10 ) = - 0,2 
c2 = ( - 4 - 6 ) : ( - 10 ) = 1 
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1 - 25c² = ( 1 - 5c )( 1 + 5c ) 
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[ ( 1 - 5c )( c - 1 ) ] / [ ( 1 - 5c )( 1 + 5c ) ] = ( c - 1 ) /( 1 + 5c ) 
ОТВЕТ ( с - 1 ) / ( 1 + 5с )