I’ve been stuck in this question and I still don’t get it

Answer:
Step-by-step explanation:
[tex]\frac{1}{3}k + 80 = \frac{1}{2}k +120\\\\\frac{1*2}{3*2}k+80=\frac{1*3}{2*3}+120\\\\\frac{2}{6}k+80=\frac{3}{6}k + 120\\\\80 = \frac{3}{6}k - \frac{2}{6}k +120\\\\80 = \frac{1}{6}k + 120\\\\80-120=\frac{1}{6}k\\\\-40 = \frac{1}{6}k\\\\-40*6=k\\\\-240 = k[/tex]