How did I get this answer please.
Favorites|Homepage
Subscriptions | sitemap
HOME > > How did I get this answer please.

How did I get this answer please.

[From: ] [author: ] [Date: 11-12-10] [Hit: ]
............


2x = 3y + 4.......................................… - 5y = 6
2x - 4 = 3y......................................… = 5y + 6---will come in handy later
2/3x - 4/3 = y

Substitution

2/3 (5y+6) -4/3 = y
10/3 y + 4 -4/3 = y
10/3 y + 8/3 = y --------> Subtract 10/3y
8/3 = -7/3y -----------> divide by -7/3 to get y
y = -8/7--------> Y

FIND X

X - 5Y = 6
X - 5(-8/7) = 6
X = 2/7

DOUBLE CHECKING:
2X = 3Y + 4
2(2/7) = 3(-8/7) + 4
4/7 = -24/7 + 4
4/7 = -24/7 + 28/7
4/7 = 4/7 ------------IT WORKS!!!


SO, ANSWER IS (2/7, -8/7)

-
Put first equation in standard form: 2x - 3y = 4
Multiply 2nd eqn by -2: -2x + 10y = -12
Add them: _______________
7y = -8
I am getting y = -8/7, not y = -2!

Jen
12
keywords: please,How,this,did,get,answer,How did I get this answer please.
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .