If two lines 6x-y=-5 and ax+2y= 7 are parallel, then a equals?
Please help.
If 2 lines are parallel, then they must have the same slope. First rewrite the lines in slope-intercept form:
$\displaystyle y=6x-5$
$\displaystyle y=-\frac{a}{2}x+\frac{7}{2}$
Thus, we can say that $\displaystyle 6=-\frac{a}{2} \implies \color{red}\boxed{a=-12}$.
I hope this makes sense!!