Question

giúp tui folow

Answer 1

a.

\(\Leftrightarrow4x^2-12x-4x^2-10x=7x-21\)

\(\Leftrightarrow-22x-7x+21=0\)

\(\Leftrightarrow\)\(-29x=-21\)

\(\Leftrightarrow x=-\dfrac{21}{-29}=\dfrac{21}{29}\)

b.

\(\Leftrightarrow x^2-7x+2x-14-2x-6=x^2+5x\)

\(\Leftrightarrow x^2-7x-20-x^2-5x=0\)

\(\Leftrightarrow-12x=20\)

\(\Rightarrow x=\dfrac{20}{-12}=-\dfrac{5}{3}\)