As written, this is
[tex]\dfrac{10}{7}k+\dfrac{11}{7}-2k+\dfrac{2}{7}+\dfrac{2}{7}k-6=\left(\dfrac{10}{7}-2+\dfrac{2}{7}\right)k+\left(\dfrac{11}{7}+\dfrac{2}{7}-6\right)\\\\=\dfrac{10-14+2}{7}k+\dfrac{11+2-42}{7}\\\\=-\dfrac{2}{7}k-\dfrac{29}{7}[/tex]
