Question

Use elimination to find the solution to the system of equations.
9x+5y=78
4x-7y=7

Answer 1

Well what I will do is multiply equation 1 by 7 and multiply equation 2 by 5. and subtract the two equations. That way you have eliminated y.

Answer 2

so you know elimination is one of the many methods used to solve simultaneous equations.
the objective is to make the coefficients of one of the variables equal and opposite so that when you add the 2 equivalent equations that variable will be eliminated.
you can then solve the equation for the one unknown.
with this value substitute in the expression for the "eliminated" variable and get the value.
it is a very good practice to check the solution in either of the originals because it is extremely easy to make mistakes.

Answer 3

@khally92 you would need to add the 2 equations

Answer 4

Yes add not subtract.

Answer 5

@ao77ao77 follow the directions and let us know if you need more help

Answer 6

http://www.montereyinstitute.org/courses/DevelopmentalMath/COURSE_TEXT2_RESOURCE/U14_L2_T2_text_final.html


This will help.