Question

write the equation of a line with the given information: (4,8) and (16,32)

Answer 1

Do you know how to calculate the slope from that info?

Answer 2

use the slope formula m=y2-y1
--------- < divided by
x2-x1
(4,8) (16,38)
x1,y1 x2, y2

plug them in to find your slope.
m=38-8
----- < divided by m=3.75 or 15/4
16-8
so now you use y=mx+b - y=yalue, m=slope, x=x value & b=y-intercept
one of your y values is 8 [you can use 38 if you want]
8=3.75(4)+b
8=15+b
b=-7

your final formula is y=15/4x-7