Решить ! а) -3х-1=0 б)2х+7=5 в)5х-2=0 г)9-4х=1

  а) -3х-1=0 -3x=1x=-1/3б)2х+7=5 2x=5-72x=-2x=-1в)5х-2=0 5x=2x=2/5г)9-4х=14x=8x=2

1) - 3x - 1 = 0      3x = - 1      x = ( - 1/3 ) 2) 2x + 7 = 5      2x = - 2      x = ( - 1 )  3) 5x - 2 = 0     5x = 2      x = 0.4  4) 9 - 4x = 1      4x = 8      x = 2

1) x² + 2 - 3 + x = 0 x² + x - 1 = 0 d = b² - 4ac = 1 - 4×(-1) = 5 x1,2 = ( - 1 + √5) / 2 2) 5x + 2 - 2 + 2x² = 0 2x² + 5x = 0 x( 2x + 5) = 0 x =0 2x + 5 = 0 2x =- 5 x =- 2,5 3) 2x² + 3 - 3 + 7x = 0 2x² + 7x = 0 x( 2x + 7) = 0 x = 0 2x+ 7 = 0 2x = - 7 x = - 3,5 4) x² - 6x - 4x + 25 = 0 x² - 10x + 25 = 0 d = b² - 4ac = 100 - 4×25 = 0 - имеет один корень. x= - b/2a x = 10/2 x = 5 5) x² + 2x - 16x + 49 = 0 x² - 14x + 49 = 0 d = b² - 4ac = 196 - 4×49 = 0 - имеет один корень. x =- b/2a x = 14/2 x = 7

1) 3x² + 9 - 12x + x² = 0 4x² - 12x + 9 = 0 d = b² - 4ac = 144 - 16×9 = 0 x = -b/2a x = 12/8 x = 1,5 2) 5x² + 1 - 6x + 4x² = 0 9x² - 6x + 1 = 0 d = b² - 4ac = 36 - 36×1 = 0 x = -b/2a x = 6/18 x = 1/3 3) x² + 2x - 3 = 0 d = b² -4ac = 4 - 4×(-3) = 26 = 4² x1 = ( - 2 + 4) / 2 = 1 x2 = ( - 2 - 4) / 2 = - 3 4) x² + 3x -4 = 0 d = b²- 4ac = 9 - 4×(-4) = 25 = 5² x1 = ( - 3 + 5) / 2 = 1 x2 = ( - 3 - 5) / 2 = - 4 5) x² - 5x + 4 = 0 d = b² - 4ac = 25 - 4×4 = 9 = 3² x1 =( 5 + 3) / 2 = 4 x2 = ( 5 - 3) / 2 = 1 6) x² - 4x + 3 = 0 d = b - 4ac = 16 - 4×3 = 4 = 2² x1 = ( 4 + 2) / 2 = 3 x2 = ( 4 - 2) / 2 = 1 7) 2x² + x - 3x - 4 = 0 2x² - 2x - 4 = 0 x² - x - 2 = 0 d = b² - 4ac = 1 - 4×(-2) = 9 = 3² x1 = ( 1 + 3) / 2 = 2 x2 = ( 1 - 3) / 2 = - 1 8) 2x² - 3x - 4x + 3 = 0 2x² - 7x + 3 = 0 d = b²- 4ac = 49 - 8×3 = 25 = 5² x1 = ( 7 + 5) / 4 = 3 x2 = ( 7 - 5)/ 4 = 0,5