Answer :
[tex]5(1.2k+6)=7.1k+34.4 \\\\ 6k+30=7.1k+34.4 \\\\ 6k-7.1k=34.4-30 \\\\ -1.1k=4.4 \\\\ \boxed{k=-\frac{4.4}{1.1}=-4}[/tex]
[tex]5(1.2k+6)=7.1k+34.4\\\\5\times1.2k+5\times6=7.1k+34.4\\\\6k+30=7.1k+34.4\ \ \ \ \ |subtract\ 30\ from\ both\ sides\\\\6k=7.1k+4.4\ \ \ \ \ \ |subtract\ 7.1k\ from\ both\ sides\\\\-1.1k=4.4\ \ \ \ \ |divide\ both\ sides\ by\ (-1.1)\\\\\boxed{k=-4}[/tex]
