College Algebra
posted by Chris .
Solve using Elimination or Substitution:
4x^2+9y^2=36
x+3y=3

Ideal for substitution
from the 2nd : x = 3  3y
sub into 1st
4(33y)^2 + 9y^2 = 36
36  72y + 36y^2 + 9y^2 = 36
45y^2  72y = 0
5y^2  8y = 0
y(5y8) = 0
y = 0 or y = 8/5
if y = 0 , x = 3
if y = 8/5 , then x = 324/5 = 9/5
intersection points (3,0) and (9/5, 8/5) 
Thanks for the help.