Exercise 56 Page 265

a The total number of birds they saw is the sum of the grebes (G), ducks (D), cormorants (C), geese (E), and spoonbills (S).

G + D + C + E + S

We could also express the number of birds with respect to where they were seen — the beach (B), the lake (L), or the field (F).

B + L + F

b Notice that

L

represents the total number of birds at the lake. If we divide this by the total number of birds they saw, we can determine the percentage of birds that were seen at the lake. We have two ways we can express this.

\frac{L}{B + L + F} or \frac{L}{G + D + C + E + S}

c Similar to Part B, we have to divide the number of birds that were geese (E) or ducks (D) by the total number of birds. We have two ways we can express this.

\frac{E + D}{B + L + F} or \frac{E + D}{G + D + C + E + S}

Subchapter links

5.2.1 Generating and Investigating Sequences p.264-265

5.2.2 Generalizing Arithmetic Sequences p.269-270

5.2.3 Recursive Sequences p.273-274