For each of the subsets of the two properties (a) and (b), count the number of four-digit numbers whose digits are either 1, 2, 3, 4, or 5.
(a) The digits are distinct.
(b) The number is even.
Note that there are four problems here: (1) when both conditions are met; (2) when only condition (a)
is met; (3) when only condition (b) is met; (4) when neither condition is met.

answer: 590

step-by-step explanation:

answer: y=0 if that is what u r looking for

statement #3: proof- ang is congruent to ang ecd : angles are congruent.  

step-by-step explanation:

1: the missing angles in statement #3  

a.) acb  

reason- the reason why the answer is acb is because angle ecd and angle acb are both the same size *that's what the word congruent means this is really simple.  

2: the missing word in reason #3  

c.) vertical  

reason- the reason why the answer is vertical is because the angles in that diagram on figure 2 is slanted, which is vertical, and the e and a both lay on vertical lines. along with the other's, but e and a are the 2 main points you want to focus on. and c is kind of like your starting point, because c is for both angles, not just one.  

i hope that was and understanding.