Question

Simplify: $\left(\right(4\times {10}^{-2})-(2.5\times {10}^{-3}\left)\right)\left({10}^4\right)$

Answer 1

$Now((4\times {10}^{-2})-(2.5\times {10}^{-3}))\left({10}^4\right)$

$\to (4\times {10}^{-2})\left({10}^4\right)-(2.5\times {10}^{-3})\left({10}^4\right)$

$\to 4\times {10}^{-2+4}-2.5\times {10}^{-3+4}$

$\to 4\times {10}^2-2.5\times {10}^1$

$\to 400-25$

$\to 375$