Former humanities/arts guy that is transitioning into computer science, namely software development. I am also fond of mathematics but merely as a hobby. Currently pursuing a degree in computer science at a university in North America. It feels great to be a part of this awesome & supportive...
After feedback.
Let p be a even integer & q be any positive integer.
Given that even number*even number is even
& even number*odd number is even, then..
p=2m
pq= 2mq
pq= 2(mq)
Let k=mq
pq=2k
Hence pq is even. :)
Proof:
Let a be a even positive integer of the form a=2m & b of the form b=2n (This is where b is a even positive integer)
ab = 2m*2n
= 2(mn)
= Let k = mn
= 2k
Therefore, ab is even.
Let a be a even positive integer a=2m & b be a odd positive integer b = 2n+1
ab = (2m)*(2n+1)...
Summary:: Prove that if a is an odd integer and b is an odd integer then a+b is even.
Theorem: If a is odd and b is odd then a+b is even.
Proof: Let a and b be positive odd integers of the form a = 2n+1 & b = 2m+1
a+b = 2n+1+2m+1
= 2n+2m+1+1
= 2n+2m+2
= 2(n+m)+2...
Commutative property of addition.
If a & b are integers then,
a+b = b+a
2+3 = 3+2
5.
Does not work for subtraction.
2-3 = -1
3-2= 1
Having said that, what about the special case with negative numbers (when we also move their respective signs)
-5 + 7 = 2 & 7 + (-5) = 2.
15 -7 = 8 & -7 + 15...
Thank you!
J= John is telling the truth.
B= Bill is telling the truth.
S= Sam is telling the truth.
J v B
~S v ~B
------------
Therefore, J v ~S
J B S J v B ~S v ~B J v ~S
F F F F...
Let P stand for John is telling the truth.
Let Q stand for Bill is telling the truth.
Let R stand for Sam is lying.
P v Q
R v Q
-----------
Therefore P v R
P Q R P v Q R v Q P v R
F F F F F F
F F T...