a: \(\Leftrightarrow3\left(x-1-4x^2+4x\right)+4\left(3x^2+9x+2x+6\right)=80\)
\(\Leftrightarrow3\left(-4x^2+5x-1\right)+4\left(3x^2+11x+6\right)=80\)
\(\Leftrightarrow-12x^2+15x-3+12x^2+44x+24=80\)
=>59x+21=80
=>x=1
b: \(\Leftrightarrow5\left(2x^2+4x+3x+6\right)-2\left(5x^2-5x-4x+4\right)=128\)
\(\Leftrightarrow10x^2+35x+30-10x^2+18x-8=128\)
=>53x=106
hay x=2
c: \(\Leftrightarrow2x^2+3x^2-3=5x^2+5x\)
=>5x=-3
hay x=-3/5
d: \(\Leftrightarrow x^2+4x+4-x^2+4x-4=8x\)
=>8x=8x
=>0x=0(luôn đúng)
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