Linear Equations
posted by Mia on .
Can you please help solve this equation using the substitution method? I have tried and keep getting that X and Y = 7/2, but the answer in the book states no solution, inconsistent system. What am I doing wrong? Please help! Solve the systems of equations by the substitution method.
yx=4
xy=3
Thank you!

Here is why there is no solution ...
multiply the first equation by 1
x  y = 4
subtract the second equation ...
0 = 7 >>>> CONTRADICTION! So, no solution.
OR
by substitution,
first equation: y = x+4
sub into second
xy = 3
x  (x+4) = 3
xx4=3
0 = 7, same result.
Your answer of x = y = 7/2 does not work in either equation. 
Solve the following system of equations by the substitution method.
8x = 2y + 5
3x = y + 7 
YX=4...(EQN 1)
XY=3...(EQN 2)
MAKING X THE SUBJECT IN EQN 2
X=3+Y
SUBSTITUTING IN EQN 1
Y(3+Y)=4
Y3Y=4
THE Y GETS ELIMINATED,HENCE THERE IS NO SOLUTION