how to solve -7x+9y=18 and 4x+9y=-18 using elimination
in Algebra 1 Answers by

Your answer

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
To avoid this verification in future, please log in or register.

1 Answer

-7x+9y=18...............................eq1

4x+9y=-18...............................eq2

eq1-eq2 (to eliminate y)

-7x-4x+9y-9y=18+18

-11x=36

x=-36/11

substituting for x in eq1 we get

-7(-36/11)+9y=18

252/11+9y=18

9y=18 -252/11

9y=(198-252)/11

9y=-54/11

y=-54/(11)(9)

y=-6/11

 

by Level 8 User (32.3k points)

Related questions

1 answer
1 answer
1 answer
asked Sep 6, 2022 in Algebra 1 Answers by anonymous | 345 views
2 answers
1 answer
1 answer
1 answer
1 answer
asked Oct 12, 2012 in Algebra 2 Answers by ayeitsNique Level 2 User (1.7k points) | 785 views
1 answer
asked Dec 18, 2013 in Other Math Topics by andijo Level 1 User (140 points) | 723 views
1 answer
asked Apr 24, 2013 in Algebra 2 Answers by anonymous | 1.2k views
Welcome to MathHomeworkAnswers.org, where students, teachers and math enthusiasts can ask and answer any math question. Get help and answers to any math problem including algebra, trigonometry, geometry, calculus, trigonometry, fractions, solving expression, simplifying expressions and more. Get answers to math questions. Help is always 100% free!
87,516 questions
100,308 answers
2,420 comments
750,076 users