SOLUTION: need help with this problem. example with explanation, please. I want to understand the basics. 1. 6x - y = -9 x + 2y = 5

Algebra.Com
Question 1095919: need help with this problem. example with explanation, please. I want to understand the basics.
1. 6x - y = -9
x + 2y = 5

Found 2 solutions by ikleyn, josgarithmetic:
Answer by ikleyn(52781)   (Show Source): You can put this solution on YOUR website!
.
There are several ways to solve this system.

Solution 1. Substitution method.

6x -  y = -9,    (1)
 x + 2y =  5.    (2)


From equation (2), express x = 5-2y.  Then replace x in the equation (1) by (5-2y).

It is the substitution step. You will get a single equation in one unknown y:

6*(5-2y) - y = -9.


Simplify and solve for y:

30 - 12y - y = -9  ====>  30 + 9 = 12y + y  ====>  39 = 13y  ====>  y =  = 3.


Now substitute  y= 3 into equation (2). You will get

x + 2*3 = 5  ====>  x = 5 - 6 = -1.


Answer.  The solution is  x= -1,  y= 3.

For more examples and explanations, see the lesson
    - Solution of the linear system of two equations in two unknowns by the Substitution method
in this site.


Let me know if my responce was useful to you.
If you have questions, you can send them to me through the "Thank you" form.

If I see the interest from your side, I will write you more about different methods of solution to this system,
and will refer more lessons in this site to you.



Answer by josgarithmetic(39617)   (Show Source): You can put this solution on YOUR website!
Equivalent system,





and you should be able to do the rest.

RELATED QUESTIONS

I need a brush-up on completing the square. I am working with equations for ellipses. I... (answered by Edwin McCravy)
I'm having trouble understanding how to solve radicals with roots. I understand the... (answered by Alan3354)
Please help me with understanding how to solve each system by graphing. For example, I... (answered by stanbon)
I need some help with this problem, please include steps to better understand. Thank You... (answered by ReadingBoosters)
I am having trouble starting off with this equation. I don't want the answer. I just... (answered by stanbon)
please i need help with this problem find the maximum value of y=... (answered by stanbon)
i dont understand anythingabout proofs and i need help starting with the... (answered by nyc_function)
I need help please with this graphing problem by solving each system by addition... (answered by Mathtut)
could you show me step by step how to figure this out Plz this is an example I don't want (answered by mananth)