\(-4\left(x-10\right)+5=-2x-\left(x+7\right)-\left(-20+8\right)\)
\(\Leftrightarrow-4x+40+5=-2x-x-7+20-8\)
\(\Leftrightarrow-4x+2x+x=-40-5-7-20-8\)
\(\Leftrightarrow-x=-80\)
\(\Leftrightarrow x=80\)
Vậy...
−4(x−10)+5=−2x−(x+7)−(−20+8)−4(x−10)+5=−2x−(x+7)−(−20+8)
⇔−4x+40+5=−2x−x−7+20−8⇔−4x+40+5=−2x−x−7+20−8
⇔−4x+2x+x=−40−5−7−20−8⇔−4x+2x+x=−40−5−7−20−8
⇔−x=−80⇔−x=−80
⇔x=80⇔x=80
−4(x−10)+5=−2x−(x+7)−(−20+8)−4(x−10)+5=−2x−(x+7)−(−20+8)
−4x+40+5=−2x−x−7+20−8⇔−4x+40+5=−2x−x−7+20−8
−4x+2x+x=−40−5−7−20−8⇔−4x+2x+x=−40−5−7−20−8
−x=−80⇔−x=−80
x=80
