or A line has a slope of 4 and includes the points (8,a) and (10,0). What is the value of a?

Answer 1

Hi,

First, write an equation of line with slope=4 and given point as (10,0)

y= mx + b ===> y = 4x + b ====> replace point into this equation ====> 0 = 4(10) + b ==> b = -40

Now you have: y = 4x -40

Second, replace the other point such as (8,a)=====> y = 4x -40 ====> a = 4(8) -40 = -8 so a = -8

I hope it is helpful,

Minoo

Answer 2

If the equation of the line is given by: y = m* x + b, then the slope is m=4.

Now if we plug in the point (x=10,y=0) into the equation, we have:

0 = 4 * 10 + b

which yields b= -40. In other words, y = 4x - 40. Now we can use the point (x=8,y=a) the same way:

a = 4*8 -40 32 -40 =-8.

so the line equation is y = 4x - 40 and a=-8.