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# Helppppp Please ( solving system of equations)

3x+4y=9
4x-37=-13

### 2 Answers by Expert Tutors

Philip P. | Effective and Affordable Math TutorEffective and Affordable Math Tutor
4.9 4.9 (416 lesson ratings) (416)
1
3x+4y=9
4x-37=-13

OK, you did write the equations down incorrectly.  They should be:

3x+4y = 9
4x-3y = -13

Let's re-write them in standard form y = mx+b

3x+4y = 9
4y = 9 - 3x
y = (9/4) - (3/4)x

4x-3y=-13
-3y = -13 - 4x
y = (13/3) + (4/3)x

Now set the two equations equal.  This is the point where the two lines intersect:

(9/4) - (3/4)x = (13/3) + (4/3)x
(9/4) - (13/3) = (4/3)x + (3/4)x
-25/12 = (25/12)x

-1 = x

Solve for y by plugging x = -1 into either original equation:

3x + 4y = 9
3(-1) + 4y = 9
-3 + 4y = 9
4y = 12

y = 3

wow thank you so much!
see the answers could only be

A. (-1,-3)
B. no solution
C. infinitely many solutions
D. (-1,3)
Oops, I plugged in x=3 instead of x=6, so the y value is -9/4 vice 0.

Since (6,-9/4) is not one of the options, did you write the equations down correctly?
You did write the equations down incorrectly - the second equation should be 4x-3y=-13 vice 4x-37=-13. I've corrected the answer above.
LOL! You are more patient than I am. I noticed that, and decided to step away from this problem. Lots of time wasted.
You were probably the wiser one of the two of us.  That second equation - without a y term - was suspect.  But once I made the mistake of stepping in, I needed to try to figure it out.  ;-)