Posted by Denis Borris on October 21, 2002 at 02:11:58:
In Reply to: Pre calculus posted by sonny on October 20, 2002 at 23:33:47:
: Solve the system by substitution
: 3x + 5y = -3 [1]
: x - 5y = -5 [2]
[2] x = 5y - 5
3(5y + 5) + 5y = -3 (subs in [1])
15y + 15 + 5y = -3
20y = -18
finish it!
: Solve the system by elimination
-5x + 2y = -6 [1]
10x - 7y = 34 [2]
-10x + 4y=-12 ([1] times 2)
add: -3y = 22 : you've "eliminated" the x (I think that's what elimination means)
finish it!