Odd numbers take the form 
, where 
is an integer. When 
, the last odd number would be 799. So we're adding
By reversing the order of terms, we have
and we can pair up terms in both sums at the same position to write
so that we are basically adding 400 copies of 800, and from there we can find the value of the sum right away:
###
We could also make use of the formulas,
We have
Answer: factors of 10 are 1, 2, 5, and 10.
Step-by-step explanation: You can also look at this the other way around: if you can multiply two whole numbers to create a third number, those two numbers are factors of the third. 2 x 5 = 10, so 2 and 5 are factors of 10.
Okay, so with the link we can tell this:
flour and baking soda are equal ratios
salt is one half the ratio of flour/baking soda
A: correct
flour and baking soda as equal ratios
B: incorrect
salt is at an incorrect ratio to flour
C: correct
salt is at a correct ratio to baking soda
D: incorrect
salt is at an incorrect ratio to baking soda
E: correct
baking soda is at a correct ratio to salt
answers: A, C , E
