Question

How do I solve y=5x-1 and y=15x-1

Answer 1

$5x-1=15x-1\Rightarrow x=0\Rightarrow y=-1$

Answer 2

$\left \{ {{y=5x-1} \atop {y=15x-1}} \right. \\ \\ (5x-1)=15x-1 \\ (5x-1)+1=(15x-1)+1 \\ 5x=15x \\ (5x)-5x=(15x)-5x \\ 0=10x \\ \frac{0}{10} = \frac{10x}{10x} \\ 0=x \\ \\ y=5(0)-1 \\ y=0-1 \\ y=-1 \\ \\ solution:(0,-1)$