Bobby claims that Peter started with 21 cards. Which statements are true about verifying Bobby’s claim? Check all that apply. A. Substitute 21 for x in the original equation.
B. Substitute any number for x in the original equation.
C. Bobby’s claim that x = 21 is correct.
D. The result of verifying Bobby’s work is 9 = 9.
E. The result of verifying Bobby’s work is 21 = 21.

step-by-step explanation:

what does 'mandy have ben 780 bottle caps. ' mean?

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.