slope intercept form is written as y=mx+b. m is the slope, and b is the y-intercept. -3=m
we know that (-5,-1) is 5 points away from the origin, and that the slope is -3, so 5 times -3 equals -15. subtract 15 from -1 (y-coordinate) in order to get the y-intercept (when x=0).
An easy way is to pretend that 25 is positive. 14+25= 39. If we know that the mathematical equation of positive+negative= negative, then we switch the 39 to -39.
