Write in point-slope form an equation of the line through the pair of points. (3,12) and (5,9)

Question

asked Mar 5, 2020 218k views

1 Answer

Jakub Linhart · Answer 1 · 2020-03-11T02:16:45+0000

Answer:

$\large\boxed{y=-(3)/(2)x+16(1)/(2)\to y=-1.5x+16.5}$

Explanation:

The slope-intercept form of an equation of a line:

y=mx+b

m - slope

b - y-intercept

The formula of a slope:

m=(y_2-y_1)/(x_2-x_1)

We have the points (3, 12) and (5, 9).

Substitute:

m=(9-12)/(5-3)=(-3)/(2)=-(3)/(2)

Put the value of a slope and coordinates of the point (3, 12) to the equation of a line:

12=-(3)/(2)(3)+b

12=-(9)/(2)+b

12=-4(1)/(2)+b add
to both sides

$16(1)/(2)=b\to b=16(1)/(2)$

Finally:

y=-(3)/(2)x+16(1)/(2)