Question

If a rectangle has a width of (2 x 10^4) cm and a length of (8 x 10^7)cm, what is the area of the rectangle ,expressed in scientific notation

Answer 1

Area = length×width
= (8·10⁷ cm)×(2·10⁴ cm) = 16·10¹¹ cm² = 1.6·10¹·10¹¹ cm²
= 1.6·10¹² cm²

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The applicable rule for exponents is
10^b × 10^c = 10^(b+c)