Question

How do you evaluate the expression `(18 xx 10^4) -: (6 xx 10^3)`?

Answer 1

First, we can rewrite this expression as:

`(18 xx 10^4)/(6 xx 10^3)`

Which we can again rewrite as:

`18/6 xx 10^4/10^3 = 3 xx 10^4/10^3`

We can now divide the 10s terms using this rule for exponents:

`x^color(red)(a)/x^color(blue)(b) = x^(color(red)(a)-color(blue)(b))`

`3 xx 10^color(red)(4)/10^color(blue)(3) = 3 xx 10^(color(red)(4)-color(blue)(3)) = 3 xx 10^1`