\(a,5\left(x-3\right)-4=2\left(x-1\right)\\ =>5x-15-4=2x-2\\ =>5x-15-4-2x+2=0\\ =>3x-17=0\\ =>3x=17\\ =>x=\dfrac{17}{3}\)
\(b,x^2-x-6=0\\ =>x^2+2x-3x-6=0\\ =>x\left(x+2\right)-3\left(x+2\right)=0\\ =>\left(x-3\right)\left(x+2\right)=0\\ =>x=3;x=-2\)
c, đk : x khác -3 ; 3
\(\Rightarrow x^2+6x+9-x^2+6x-9=36\Leftrightarrow12x=36\Leftrightarrow x=3\left(ktm\right)\)
pt vô nghiệm
d, \(\Rightarrow6x-3-5x+10=x+7\Leftrightarrow x+7=x+7\)
pt vô số nghiệm