Question

$x^{2} -4x=3(2-x)$

Answer 1

x^2-4x=6-3x
x^2-4x+3x=6
x^2-x-6=0
delta=1+24=25
x1=(1+√25)/2=(1+5)/2=6/2=3
x2=(1-√25)/2=(1-5)/2=(-4/2)=(-2)

Answer 2

$\displaystyle x^2-4x=3(2-x) \\ \\ \text{Inmultim pe 3 cu fiecare termen din paranteza.} \\ \\ x^2-4x=6-3x \\ \\ \text{Trecem tot in partea stanga cu semn schimbat.} \\ \\ x^2-4x-6+3x=0 \\ x^2-x-6=0 \\ \\ \Delta=b^2-4ac \\ \Delta=(-1)-4\cdot1\cdot(-6)\\ \Delta=25 \\ \\ X_{1,2}= \frac{-b\pm \sqrt{\Delta} }{2a}= \frac{1\pm5}{2} \\ \\\\ X_1= \frac{6}{2}=3 \\ \\ X_2= \frac{-4}{2} = -2$