Which expression represents the volume, in cubic units, of the composite figure?

a) π(103) + π(102)(28)
b) π(203) + π(202)(28)
c) 2π(103) + π(102)(28)
d) 2π(203) + π(202)(28)

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?

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Identify the expression equivalent to 4(x + x + 7) − 2x + 8 − 4 by substituting x = 1 and x = 2.