Ask your own question, for FREE!
Mathematics 21 Online
OpenStudy (anonymous):

Terrible at math, need help with college algebra.

OpenStudy (anonymous):

...Which part of college algebra?

OpenStudy (anonymous):

The Substitution Method Solutions to Systems of Linear Equations Applications of the Substitution Method

OpenStudy (anonymous):

Okay, say you have two linear equations that need solving.\[a*x + b*y = c\] and \[d*x+e*y=f.\] Now, you solve one equation for x:\[x = (c-b*y)/d.\] Plug that value for x into your second equation, and solve for a value of y.

OpenStudy (anonymous):

After you have that value of y, you plug it back into either equation, and you'll get the value of x. :)

OpenStudy (amistre64):

its really simpler than it looks :)

OpenStudy (anonymous):

(Assuming a-f are regular constants.)

OpenStudy (anonymous):

So for x-2y=1 3x+12y+15 i am suppossed to find whether the lines are parallel or coinciding...

OpenStudy (anonymous):

You mean, 3x+12y = 15?

OpenStudy (amistre64):

It depends on what is being asked for in the problem.

OpenStudy (amistre64):

oh...that is the problem..thought it was a question lol

OpenStudy (anonymous):

yes and i have to write these in slope intercept form

OpenStudy (anonymous):

If they coincide, or are the exact same line, then one equation will be the same as the other equation -- just multiplying every term by the same factor.

OpenStudy (amistre64):

do you know how to solve each equation for "y"?

OpenStudy (amistre64):

x - 2y = 1; how would you solve for "y"?

OpenStudy (anonymous):

I amnot sure....

OpenStudy (amistre64):

we have to go back to the basics of equations with this; we want to get that "y" all by itself on one side of the equation and everything else to the other side; does that sound familiar?

OpenStudy (amistre64):

the basic rule of thumb is: whatever you do to one side, HAS to be done to the other inorder for it to stay equal.

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!