Show if lines are parallel, perpendicular, or neither

Y=10x-2

-10x+y=4

Solve the second equation for y

-10x+y=4

y=10x+4

so we have the 2lines

y=10x-2

y=10x+4

both are written in slope intercept form do the coefficient of x is there slope. since both slopes are the same, namely 10, the two lines are parallel

The lines are parallel bc if you change - 10x+y=4 into y=10x+4 they will have the same slope of m=10x