Question

Drag the tiles to the correct boxes to complete the pairs. Not all tiles will be used.

Match each exponential function to the description of its percent rate of change.
22% growth
12% decay
12% growth
22% decay
2% decay
2% growth
20% growth
20% decay
RX) = 42(1.12)*
Rx) = 44(0.88)*
R(X) = 22(0.8)*
RX) = 124(1.22)*

Answer 1

Top to Bottom:

• 12% growth
• 12% decay
• 20% decay
• 22% growth

Explanation:

Subtract 1 from the number in parentheses (the base of the exponential factor). Multiply the result by 100%. This gives you the percentage growth (positive) or decay (negative).

(1.12 -1)×100% = +12% (growth)

(0.88 -1)×100% = -12% (decay)

(0.80 -1)×100% = -20% (decay)

(1.22 -1)×100% = +22% (growth)

_____

The sign of the change (+ or -) and the description (growth or decay) convey the same information. It can be confusing to say -12% decay. Rather, the decay is 12%, or the growth is -12%. Above, we tried to indicate that positive is growth and negative is decay. We're not trying to say that the decay is -12%.