Question

Giải các phương trình sau:

\(g.\dfrac{5\left(x-1\right)+2}{6}-\dfrac{7x-1}{4}=\dfrac{2\left(2x+1\right)}{7}-5\)

Answer 1

\(\dfrac{5\left(x-1\right)+2}{6}-\dfrac{7x-1}{4}=\dfrac{2\left(2x+1\right)}{7}-5\)

\(\Leftrightarrow\dfrac{5x-5+2}{6}-\dfrac{7x-1}{4}=\dfrac{4x+2}{7}-5\)

\(\Leftrightarrow\dfrac{70x-70+28}{84}-\dfrac{147x-21}{84}=\dfrac{48x+24}{84}-\dfrac{420}{84}\)

\(\Leftrightarrow70x-70+28-147x+21=48x+24-420\)

\(\Leftrightarrow-125x=-375\)
\(\Leftrightarrow x=3\)

Answer 2

g) \(\dfrac{5\left(x+1\right)+2}{6}-\dfrac{7x-1}{4}=\dfrac{2\left(2x+1\right)}{7}-5\)

<=>\(\dfrac{14\left(5x-3\right)-21\left(7x-1\right)}{84}=\dfrac{12\left(4x-33\right)}{84}\)

<=>\(70x-42-147x+21=48x-396\)

<=>\(125x=375\)

<=>x=3