What is the slope-intercept form equation of the line that passes through (2, 4) and (4, 10)

Question

These are all the possible answers but i cant tell which one is correct

y = −3x − 2


y = −3x + 2


y = 3x + 2


y = 3x − 2

Answer 1

points (2,4) and (4,10)

find the slope, m

(10-4)/(4-2)=6/2=3

y=mx+b

y=3x+b

choose one of the points, such as (2,4)

4=3(2)+b

4=6+b

b=-2

y=3x-2

if you use (4,10)...

10=3(4)+b

10=12+b

b=-2 again

y=3x-2

 

Answer 2

slope is (4-10)/(2-4) = -6/-2 = 3

 

y-intercept: pick a point for (x, y), so plug in 2 for x, 4 for y and 3 for m, in slope-intercept form: y=mx+b

 

4=3(2)+b  now solve for b

4=6+b

-2=b

 

plug in m and b to y=mx+b

 

y=3x-2 is the answer