a:\(\left(x-1\right)\left(3-2x\right)+\left(2x-1\right)\left(x+3\right)=4\)
=>\(3x-2x^2-3+2x+2x^2+6x-x-3=4\)
=>10x-6=4
=>10x=10
=>\(x=\dfrac{10}{10}=1\)
b: \(\left(\dfrac{x}{2}+3\right)\left(5-6x\right)+\left(12x-2\right)\left(\dfrac{x}{4}+3\right)=0\)
=>\(\dfrac{5x}{2}-3x^2+15-18x+3x^2+36x-\dfrac{1}{2}x-6=0\)
=>\(20x+9=0\)
=>20x=-9
=>\(x=-\dfrac{9}{20}\)