x^2 - 5x = 14 x^2 - 5x - 14 = 0 D = 25 + 56 = 81 = 9^2 x1 = ( 5 + 9 ) : 2 = 7 x2 = ( 5 - 9 ) : 2 = - 2 ОТВЕТ 7 ; - 2 ----------------------------------9 + 4x^2 - 12x = 0 4x^2 - 12x + 9 = 0D = 144 - 144 = 0 x = 12 : 8 = 1,5 ОТВЕТ 1,5 -------------------------------------2x^2 - 9x - 5 = 0 D = 81 + 40 = 121 = 11^2 x1 = ( 9 + 11 ) : 4 = 5 x2 = ( 9 - 11 ) : 4 = - 0,5 ОТВЕТ 5 ; - 0,5 ----------------------------------------4x^2 = 9 + 16x 4x^2 - 16x - 9 = 0D = 256 + 144 = 400 = 20^2 x1 = ( 16 + 20 ) : 8 = 4,5 x2 = ( 16 - 20 ) : 8 = - 0,5 ОТВЕТ 4,5 ; - 0,5 ------------------------------------------3 + 4x^2 - x = 0 4x^2 - x + 3 = 0D = 1 - 48 = - 47 D < 0 ОТВЕТ нет решений-------------------------------------------------- x^2 + x = 0 x( x + 1 ) = 0 x = 0 x + 1 = 0x = - 1 ОТВЕТ 0 ; - 1 -------------------------------------------------8 - 2с^2 = 0 2( 4 - c^2 ) = 0 2( 2 - c )( 2 + c ) = 02 - c = 0c = 2 2 + c = 0 c = - 2 ОТВЕТ 2 ; - 2