Bài 2:
a: =>168x+20=6x-21
=>162x=-41
hay x=-41/162
b: \(\Leftrightarrow2\left(3x-8\right)=3\left(5-x\right)\)
=>6x-16=15-3x
=>9x=31
hay x=31/9
c: \(\Leftrightarrow4\left(x^2+8x-20\right)-\left(x+4\right)\left(x+10\right)=3\left(x^2+2x-8\right)\)
\(\Leftrightarrow4x^2+32x-80-x^2-14x-40-3x^2-6x+24=0\)
=>12x-96=0
hay x=8