Lines a and b are parallel.

what is the measure of angle m

Hello!

Since lines a and b are parallel 

The angle that equals 125 and angle m are supplementary

supplementary means they add to 180

we subtract 125 from 180 to find angle m

180 - 125 = 55

Hope this helps!

Abit confused about what you mean, but i think you might be referring to slope intercept form: y = mx + bin that case b, or the y intercept is already given.(0,-1)find the slope by using the formulay2 - y1/x2 - x1the final slope will be 4/2, equivalent to 2.now your equation should look like thisy = 4/2x -1sorry if this didn’t you out!