Help With System of Equations...

[j.m.t88]

I cannot figure out how to solve this:


The problem reads as follows:

For the system of equations {2y=3x-7
{4x=3y+10 , the value of x is...

The multiple choice options are:

a.-2
b.1
c.2
d.8
e.8 1/2


I've tried turning x into these 5 options to see what I come out with-but I am obviously doing something wrong. I really don't know where to start. Please help.

Thank you.

 

[Deleted member 4993]

I cannot figure out how to solve this:


The problem reads as follows:

For the system of equations {2y=3x-7
{4x=3y+10 , the value of x is...

The multiple choice options are:

a.-2
b.1
c.2
d.8
e.8 1/2


I've tried turning x into these 5 options to see what I come out with-but I am obviously doing something wrong. I really don't know where to start. Please help.

Thank you.

Have you been taught the solution of system of equations?

For q quick review - go to:

http://www.purplemath.com/modules/systlin1.htm

 

[j.m.t88]

Yes, I did. I can't find an equation that is similar to the one in my problem.

 

[j.m.t88]

I understand the concept on that link, but it is the "2y" and the "4y" at the beginning of this equation that is throwing me off.

 

[mmm4444bot]

I've tried turning x into these 5 options to see what I come out with-but I am obviously doing something wrong.

Nobody here can find your mistakes, unless you show us your work.

Testing each of the multiple-choices is a valid approach; it's called the "brute-force method".

After you substitute some value for x into each equation, solve each for y. The value of x that leads to the same value of y in both equations is the correct answer.

If you would like help solving the system of equations (versus using the brute-force method), you still need to show us your work.

I don't understand what you mean, when you say that the terms 2y and 4x confuse you.

 

[Deleted member 4993]

I understand the concept on that link, but it is the "2y" and the "4y" at the beginning of this equation that is throwing me off.

The problem reads as follows:

For the system of equations {2y=3x-7
{4x=3y+10 , the value of x is...

I do not see a "4y" here......

 

[fmbeach]

I think that, maybe, you are confused becuse one equation has y's on the left, the other has the x's on the left. If that's it, rewrite, say, the second one to have the y's on the left and the x's on the right.

 

[jos_iqmath2010]

The problem reads as follows:

For the system of equations {2y=3x-7
{4x=3y+10 , the value of x is...

The multiple choice options are:

a.-2
b.1
c.2
d.8
e.8 1/2

First you have to leave X alone in order to use the multiple choice that can be -infinite to +infitite so:

3x=2y+7
(3x)/3=(2y+7)/3
x=(2y+7)/3 now you use the multiple values of y(a.-e.) and here you will have one graphic line

then the same with the second equation:

4x=3y+10
(4x)/4= (3y+10)/4
x= (3y+10)/4 now you use the multiple values of y(a.-e.) and here you will have another graphic line

BOTH GRAPHIC WILL HAVE (-2,1); but the second line will be slightly tilted to the right; and because they are united on one point, this inclination will occur also at the left in the opposite direction, is like having a double helix in a single engine plane of WWII. THIS TIME A +-INFINITE DOUBLE HELIX.

PLEASE SEE THE GRAPHIC WITH BOTH EQUATIONS (RED,GREEN) AND RESPECTIVE LINES.

THANKS.