Simplify the expression. write the answer using scientific notation. the quantity 0.4 multiplied by 10 raised to the power of negative 6 end of quantity multiplied by the quantity 0.7 multiplied by 10 raised to the power of negative 2 end of quantity. a. 2.8 × 10–8 b. 2.8 × 10–7 c. 0.28 × 10–9 d. 2.8 × 10–9