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A = 2.7 x 10 ³ x 6.4 x 10 ⁻⁵ = 17.28 x 10 ⁻² = 1.728 x 10 ¹ x 10 ⁻² = 1 .728 x 10 ⁻¹
B = 2.3 x 10 ⁶ x 0.17 x 10 ⁷ = 0.931 x 10 ¹³ = 9.31 x 10 ¹²
C = 5 x 10 ⁻³ x 9 x 10 ¹² x 25 x 10 ⁻⁹ = 1 125 x 10 ⁰ = 1 .125 x 10 ³
4 x 10 ⁻⁵ x 10 ⁸ = 4 x 10 ³
12 x 10 ⁻³ = 1.2 x 10 ⁻²