Fill in the blanks in the following proof, which shows that the sequence defined by the recurrence relation

sk = sk − 1 + 2k, for each integer k ≥ 1
s0 = 3.
satisfies the formula

sn = 3 + n(n + 1) for every integer n ≥ 0.

Proof (by mathematical induction):

The base of a triangle exceeds the height by 9 inches. if the area is 180 square inches, find the length of the base and the height of the triangle.

Write the expression in complete factored form. 5n_(c - 3) - n(c - 3) =

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.