Question

помогите пж номер583

Answer 1

x₁+x₂= - b - теорема Виета
x₁x₂=c

x²-9x+20=0
x₁+x₂=9 
x₁x₂=20
x₁=5
x₂=4

x²+11x-12=0 
x₁+x₂=-11 
x₁x₂=-12
x₁= -12
x₂=1

x²+x-56 =0
x₁+x₂=-1
x₁x₂=-56
x₁= -8
x₂=7

D=b²-4ac
x= \frac{-b+- \sqrt{D} }{2*a}x=2∗a−b+−D​​ 

x²-19x+88=0
D=(-19)*4*88*1=361-352=9=3²
\begin{lgathered}x_{1}= \frac{-(-19)- \sqrt{9} }{2*1} = \frac{19-3}{2} = \frac{16}{2} =8 \\ x_{2}= \frac{-(-19)+ \sqrt{9} }{2*1} = \frac{19+3}{2} = \frac{22}{2} =11 \\\end{lgathered}x1​=2∗1−(−19)−9​​=219−3​=216​=8x2​=2∗1−(−19)+9​​=219+3​=222​=11​