Expert: Richard J. Raridon - 5/20/2004

Question
graph Y=12-sqrt6x-78
     _____
Y=12-/6x-78
given x=13 find y
given y=4.254 find x
given x=25 find y
given y=6 find x
I don't know how to find the pts thanks.

Answer
You can write it y = 12 - (6x-78)^1/2
It's easy to find y if you know x.  
if x = 13, then 6x-78=0 and y = 12
if x = 25, 6x-78=72, so y = 12-(72)^1/2 = 3.515
Re-write it as (6x-78)^1/2 = 12-y
so 6x-78 = (12-y)^2 = 144 -24y +y^2
6x = 222-24y+y^2
so if y = 4.254, x = 23.0
if y = 6, x = 19.0