Вычислите с a и b.

\(a = 2.4 \cdot 10^3\), \(b = 1.2 \cdot 10^2\): \(a+b = 2.52 \cdot 10^3\), \(a-b = 2.28 \cdot 10^3\), \(a \cdot b = 2.88 \cdot 10^5\), \(a:b = 20\).