Ta có:
(x-78).(x+54)=0
\(\Rightarrow\)\(\left[{}\begin{matrix}x-78=0\\x+54=0\end{matrix}\right.\)
\(\Rightarrow\)\(\left[{}\begin{matrix}x=78\\x=-54\end{matrix}\right.\)
Vậy x \(\in\left\{78;-54\right\}\)
Nhớ like cho mình nhé
ta có:
(x-78).(x+54)=0
⇒⇒[x−78=0x+54=0[x−78=0x+54=0
⇒⇒[x=78x=−54[x=78x=−54
Vậy x ∈{78;−54}∈{78;−54}
Nhớ like cho mình nhé