Question

giúp mik với nha

Tìm nghiệm của đa thức:

a, P(x) = 4x - \(\dfrac{1}{2}\)

b, Q(x) = (x-1)(x+1)

c, A(x) = x² - 7x + 6

d, B(x) = -x² + 16

e, C(x) = x² + 6x + 11

Answer 1

a, \(P\left(x\right)=4x-\dfrac{1}{2}\)

\(\Rightarrow P\left(x\right)=4x-\dfrac{1}{2}=0\)

\(\Rightarrow x=\dfrac{1}{8}\)

b, \(Q\left(x\right)=\left(x-1\right)\left(x+1\right)\)

\(\Rightarrow Q\left(x\right)=\left(x-1\right)\left(x+1\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x-1=0\\x+1=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=1\\x=-1\end{matrix}\right.\)

c, \(A\left(x\right)=x^2-7x+6\)

\(\Rightarrow A\left(x\right)=x^2-7x+6=0\)

\(\Rightarrow x^2-6x-x+6=0\)

\(\Rightarrow x\left(x-6\right)-\left(x-6\right)=0\)

\(\Rightarrow\left(x-6\right)\left(x-1\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x-6=0\\x-1=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=6\\x=1\end{matrix}\right.\)

Answer 2

mn làm ơn giúp mik vs, thanks nhiều

Answer 3

a) x=0,125

b) x=1 hoặc x= \(-1\)

c) x=1 hoặc x=6

d) x=4 hoặc x=\(-4\)

e)\(x\in\varnothing\)