Question

49x²-4=0 chỉ mình với mn ơi'(

Answer 1

49x² - 4 = 0

<=> (7x)² - 2² = 0

<=> (7x - 2)(7x + 2) = 0

<=> \(\left[{}\begin{matrix}7x-2=0\\7x+2=0\end{matrix}\right.\)

<=> \(\left[{}\begin{matrix}x=\dfrac{2}{7}\\x=-\dfrac{2}{7}\end{matrix}\right.\)

Answer 2

\(49x^2-4=0\)

\(\Rightarrow49x^2=4\)

\(\Rightarrow x^2=\dfrac{4}{49}\)

\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{2}{7}\\x=-\dfrac{2}{7}\end{matrix}\right.\)

Answer 3

49x²- 4=0

(7x)² -2² = 0

(7x - 2).(7x + 2) = 0

7x-2 = 0 hay 7x + 2 = 0

   x = 2/7 hay       x = -2/7

vậy S= ( 2/7,-2/7)