Question

Answer 1

\(\left(5x+1\right)^2=\dfrac{36}{49}\)

\(\Leftrightarrow\left(5x+1\right)^2=\left(\pm\dfrac{6}{7}\right)^2\)

\(\Leftrightarrow\)\(\left[{}\begin{matrix}5x+1=\dfrac{6}{7}\\5x+1=-\dfrac{6}{7}\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{35}\\x=-\dfrac{13}{35}\end{matrix}\right.\)

\(\Rightarrow D\)

Answer 2

Câu D

Answer 3

mn giúp mình vs mình đang cần gấp

Answer 4

⇔(5x+1)2=(±67)2⇔(5x+1)2=(±67)2

⇔⎡⎢ ⎢⎣x=−135x=−1335