Question 213715This question is from textbook MATHPOWER 11
: Solve by elimination. Check each solution.
21. 6x-5y=-3
2y-9x=-1
Please help me out ive been stuck on this one for a while!
This question is from textbook MATHPOWER 11
Found 2 solutions by rapaljer, drj:
Answer by rapaljer(4671)   (Show Source):
You can put this solution on YOUR website! Re-write the equations in standard form:
6x-5y=-3
-9x+2y =-1
You can eliminate either the x or the y terms. In order to eliminate the y terms, you need a common multiple of the coefficients -5 and 2. That would be 10. You need to get a -10y in the first equation and a +10y in the second equation, which will make the y terms subtract out. So multiply the first equation by 2 and the second equation by 5 like this:
2(6x -5y) =2*-3
5(-9x+2y)=5*-1
12x -10y =-6
-45x +10y =-5
-33x=-11
Divide both sides by -33
x=1/3
Substitute x=1/3 back into the first equation:
6x-5y=-3
6*1/3-5y=-3
2-5y =-3
-5y=-5
y=1
Check in the second equation:
-9x+2y = -1
-9*(1/3) +2(1)=-1
-3 +2=-1
It checks!!
For additional explanation, see my website. Begin with a "Bing" search for my last name "Rapalje". Look for "Rapalje Homepage" which is at or near the top of the list. Then click on the link on my homepage that says "Basic, Intermediate, and College Algebra: One Step at a Time." Select "Basic Algebra", and look in "Chapter 4" for "Section 4.04, Solving Systems of Equations." See also my "MATH IN LIVING COLOR" section that pertains to this topic. You will probably like my "non-traditional" explanations, written to students who may have trouble with math!
R^2
Dr. Robert J. Rapalje, Retired
Seminole Community College
Altamonte Springs Campus
Florida
Answer by drj(1380)  (Show Source):
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