The nth term of a sequence is 20-n^2 a) find the third term of the sequence
b) which term in the sequence is the first to have a negative value

Bob is putting books on a shelf and takes a break after filling 18 1/2 inches on the book shelf. the book shelf is now 2/3 full. how long is the entire bookshelf?

Given: ab ≅ cd and ad ≅ bc prove: abcd is a parallelogram. statements reasons 1. ab ≅ cd; ad ≅ bc 1. given 2. ac ≅ ac 2. reflexive property 3. △adc ≅ △cba 3. ? 4. ∠dac ≅ ∠bca; ∠acd ≅ ∠cab 4. cpctc 5. ∠dac and ∠bca are alt. int. ∠s; ∠acd and ∠cab are alt. int. ∠s 5. definition of alternate interior angles 6. ab ∥ cd; ad ∥ bc 6. converse of the alternate interior angles theorem 7. abcd is a parallelogram 7. definition of parallelogram what is the missing reason in step 3? triangle angle sum theorem sas congruency theorem sss congruency theorem cpctc

Use a calculator to verify that σ(x) = 62, σ(x2) = 1034, σ(y) = 644, σ(y2) = 93,438, and σ(x y) = 9,622. compute r. (enter a number. round your answer to three decimal places.) as x increases from 3 to 22 months, does the value of r imply that y should tend to increase or decrease? explain your answer. given our value of r, y should tend to increase as x increases. given our value of r, we can not draw any conclusions for the behavior of y as x increases. given our value of r, y should tend to remain constant as x increases. given our value of r, y should tend to decrease as x increases.