Can somebody please explain this problem. Thanks
If x+y=3 what is the value x-y/y-z
A. y+z=4
B. x+z=5
If x+y=3 what is the value x-y/y-z
A. y+z=4
B. x+z=5
Statment 1 is insufficient b/c the equation does not give you a value for x.
Statement 2 is insufficient for the same reason--you are not given a value for y.
Statements 1 and 2 together--write out equations and subsitute values:
x+y=5-->x=5-z
y+z=4-->y=4-z
So in the equation given in the question, x+y=3 subsitute the x for 5-z:
5-z+y=3
Subsitute the y for 4-z:
5-z+4-z=3-->subtract 5 from both sides-->-2z+4=-2-->subtract 4 from both sides-->-z=-6-->Z=6
Substitute 6 in for z for one of the equations:y+z=4-->y+6=4-->y=-2
Substitute -2 in for y and from here you shouldn't do anymore work--you have enough info to solve for x-y/y-z, so the answer is C
