Complete the equation of the line through (2,1) and (5,-8).

Question

balls

Answer 1

line through (2,1) and (5,-8) has slope = change in y values divided by change in x values

= (1+8)/(2-5) = 9/-3

=-3 = (y-1)/(x-2)

y-1 = -3(x-2) is the equation in point slope form (using the 1st point; you can use either point)

or using (5,-8)

y+8 = -3(x-5) is the equation also in point slope form using the 2nd point given

y = -3x +6+1

y = -3x+ 7 in slope intercept form, slope =-3 intercept =7

or

3x+y = 7 in standard form where ax+by=c with a=3, b=1 and c=7

or

3x+y -7 = 0 in general form

you have your choice of 5 different equations

if you graph them, they are all the same line, through the same two given points