1) x² - 144 = 0x² = 144x = 12x = - 122) 4x² - 49 = 04x² = 49x² = 12,25x = 3,5x = - 3,53) x² + 4 = 0x² = - 4 - корней нет.4) x² - 16x + 64 =0D = b²- 4ac = 256 - 4×64 = 0 - имеет один кореньx = - b/2ax = 16/2 = 8x =85) x² - 6x + 5 = 0D = b² - 4ac = 36 - 4×5 = 16 = 4²x1 = ( 6 + 4) / 2 = 5x2 = ( 6 - 4) / 2 = 16) x² - 8x - 9 = 0D = b²- 4ac = 64 - 4×(-9) = 100 = 10²x1 = ( 8 + 10) / 2 = 9x2 = ( 8 - 10) / 2= - 17) 5x² + x = 0x( 5x + 1) = 0Произведение равно 0,когда один из множителей равен 0,значит,x = 05x + 1 = 05x = - 1x= - 1/5x = - 0,28) x² - 2x - 48 = 0D = b² - 4ac = 4 - 4×(-48) = 196 =14²x1 = ( 2 + 14) / 2 = 8x2 = ( 2 - 14) / 2 = - 69) 2x² + 6x - 8 = 0x² + 3x - 4 = 0D = b² - 4ac = 9 - 4×(-4) = 25 = 5²x1 ( - 3 + 5) / 2 = 1x2 = ( - 3 - 5) / 2 = - 410) x² + 7x + 6 =0D = b² - 4ac = 49 - 4×6 = 25 = 5²x1 = ( - 7 + 5) / 2 = - 1x2 = ( - 7 - 5) / 2 = - 6