Question

two petri dishes were on the desktop in dr. mcfarlans lab. dish a had cells with a radius of $3.8 \times 10^{-14}$ cm. dish b had cells that had a radius of $4.7 \times 10^{-12}$ cm. what is the sum of the radii of the two types of cells, using scientific notation? a. $4.738 \times 10^{-12}$ cm b. $4.738 \times 10^{-16}$ cm c. $47.38 \times 10^{-15}$ cm d. $473.8 \times 10^{-14}$ cm

Explanation:

Step1: Convert to same exponent

$3.8 \times 10^{-14} = 0.038 \times 10^{-12}$

Step2: Add the two values

$0.038 \times 10^{-12} + 4.7 \times 10^{-12} = (0.038 + 4.7) \times 10^{-12}$

Step3: Simplify the sum

$4.738 \times 10^{-12}$

Answer:

A. $4.738 \times 10^{-12}$ cm