Let Qx y be the statement x y x y If the domain for both
Let Q(x, y) be the statement x + y = x ? y. If the domain for both variables consists of all integers, what are the truth values?
a) Q(1, 1)
b) Q(2, 0)
c) ?yQ(1, y)
d) ?xQ(x, 2)
e) ?x?yQ(x, y)
f) ?x?yQ(x, y)
g) ?y?xQ(x, y)
h) ?y?xQ(x, y)
i) ?x?yQ(x, y)
Solution
We are given statement
x+y=x-y
(A)
Q(1,1)
we plug x=1 and y=1
we get
1+1=1-1
they can not be equal
so, it is false
(B)
Q(2,0)
we plug x=2 and y=0
and we get
2+0=2-0
2=2
so, this is true......Answer
(C)
y Q(1, y)
we can plug that in statement
we get
1+y=1-y
We can get equality
1=1
Hence , this is true........Answer
(D)
x Q(x, 2)
we can plug values in statment
and we get
x+2=x-2
2=-2
so, it is false.......Answer

