math
posted by lizzy on .
Test these conjectures. Give three examples. Explain if the
conjecture is correct or incorrect.
1. If a number is divisible by 4, it is always an even number._________________________________
2. All multiples of 5 have a 5 in the ones place.__________________________________
3. If a number has a 9 in the ones place, it is always divisible by 3.________________________________
4. The least common denominator of two fractions is always greater than the
denominators of the fractions.______________________________
5. Write a conjecture about the product of two odd numbers. Then test your
conjecture.__________________________________________________________
6. How is testing a conjecture like finding a statement to be true
or false? How is it different?_______________________________________________________________________________________________________________________

1incorrect ex.26,106, and 102
2incorrect ex.110,100,and 20
3incorrect ex.29,19,and 49
4i'm not positive
5the product of two odd numbers will not be divisible by a positive number. (i'm not sure)i think it's correct
6it is the same because you are finding if the conjecture works in all case or no cases or in sometimes. it is different because in some case it may be sometimes but you don't have that option. 
4. The LCD may be the same as the denominator of one of the fractions. It will never be less than both of them.
5. The product of two odd numbers is always odd. For some m and n, let the two numbers be (2m+1) and (2n+1). Why? Any multiple of 2 is even. Add 1 to make an odd number. Multiply the two numbers and get 2mn + 2m + 2n + 1 = 2(mn+m+n)+1. This is odd because it is one more than an even number.
6. Testing a conjecture is often easy. Just try some values. Proving it is true or false is usually more involved, as in the statement #5 above. 
Inncorectbecause twenty eight divided by four is seven and seven is not an even number.

some of the answers don't even make sense.