а) х^2 + 5х - 1 = - 1
х^2 + 5х = 0
х(х+5) = 0
х1 = 0; х2 = -5
б) х^2 + 5х - 1 = 5
х^2 + 5х - 6 = 0
х1•х2 = -6
х1+х2 = -5
х1 = -6; х2 = 1
в) х^2 + 5х - 1 = - 5
х^2 + 5х + 4 = 0
х1•х2 = 4
х1+х2 = -5
х1 = -4; х2 = -1
г) х^2 + 5х - 1 = - 6,25
х^2 + 5х + 5,25 = 0
Д= 25 - 4•1•5,25 = 25 - 21 = 4
√Д = √4 = 2
х1= (-5+2)/2 = -3/2
х2= (-5-2)/2 = -7/2
484x^2-324=0 |:2
242x^2-162=0 |:2
121x^2-81=0
121x^2=81
x = 9/11
x2 = - 9/11
Ответ:
Объяснение:
11(d-3)³/33(d-3)= 1/3 (d-3)²
=3x2+5x-1=x2-4x
3x2+5x-1-x2+4x=o
2x2+9x-1=o
=15a²+12ab-5ab-4b²=15a²+7ab-4b²