View Full Version : 3x 4y = -2 and 2x - 3y = 10
FusionOfCulture
May 2, 2012, 07:25 PM
3x 4y = -2 and 2x - 3y = 10
I really don't know what to do , this is my first time seeing this problem and its very hard to me because I don't know what to do , Help Please ?
naresh821
May 2, 2012, 11:00 PM
I think that there must be some sign between 3x 4y.. it seems to be a wrong/ misprint question.
Sunwillshine
May 3, 2012, 08:56 AM
Hmm there must be a sign between 3x 4y and you have to solve first in respect of y and then in respect with x
Lets say the sign that is missing is + so the equation will be 3x+4y=-2
So we start to find y:
3x+4y=-2
2x-3y=10
You can put this solution on YOUR website!
3x=-2y+4
3x/3=-2y/3+4/3
x=-2y/3+4/3
Now if I substitute this into the 2nd equation 2x-3y=6, I have:
2(-2y/3+4/3)-3y=6
-4y/3+8/3-3Y=6
-4Y/3-3Y=6-8/3 combine the y terms by finding a common denominator (3).
(-4Y-3Y*3)/3=(6*3-8)/3
(-4Y-9Y)/3=(18-8)/3 cancel out the 3 in the denominators.
-13y=10
y=-10/13 ans.
Replace y by (-10/13) in the first equation.
3x=-2(-10/13)+4
3x=20/13+4 divide both sides by 3.
x=20/13*1/3+4/3
x=20/39+4/3 find the common denominator (39).
x=(20+4*13)/39
x=(20+52)/39
x=72/39 reduce the fraction.
x=24/13 ans.