1) x²+0x+25=0 2) (x+6)/7 - (x-6)/5 +(2x-1)/4=3/5 - вопрос №433441910250267652143532532341427 от GEgor004 25.03.2021 21:21

Question

Алгебра: 1) x²+0x+25=0 2) (x+6)/7 - (x-6)/5 +(2x-1)/4=3/5 3) 2x-5=3/2 - 3/4 +1 4) (2x-7)/3 +(2-3x)/4=5- (x/12) - 41/6 5)x+(2/7)=(7x-3)/7

GEgor004 · Answer

1) x² + 25 =0D = b² - 4ac = 0² - 4 × 25 = - 100 - дискрименант отрицательный,значит,корней нет.ответ:корней нет.2) (20x + 120 - 28x + 168 + 70x - 35) / 140 = 3/5(62x + 253) / 140 = 3/55( 62x + 253) = 140 × 3310x + 1265 = 420310x = - 1265 + 420310x = - 845x = - 845 / 310x = - 169/623) 2x - 5 = 7/42x = 5 + 7/42x = 27/4x = 27/8x =3,3754) ( 8x - 28 + 6 - 9x)/ 12 = ( 60 - x - 82) / 12( - x - 22) / 12 = ( - x - 22) /  1212( - x - 22) = 12 ( - x - 22)- 12x - 264 = - 12x - 264- 12x + 12x = 264 - 2640x =...