Question

How do you simplify `-a * -a`?

Answer 1

`(-a) * (-a) = color(green)(a^2)`

Explanation:

`(-a) * (-a)color(white)("XXX")`I've added the parentheses
`color(white)("XXXXXXXXXXX")`since having multiple operators in a row can be confusing.

`color(white)("XXX")=(-1) * a * (-1) * a`

`color(white)("XXX")=(-1) * (-1) * a * a`

`color(white)("XXX")=+1 * a^2`

`color(white)("XXX")=a^2`

Answer 2

See the entire simplification process below:

Explanation:

Use these two rules of exponents to simplify this expression:

`a = a^color(red)(1)` and `x^color(red)(a) xx x^color(blue)(b) = x^(color(red)(a) + color(blue)(b))`

`-a * -a = -a^color(red)(1) * -a^color(blue)(1) = (-a)^(color(red)(1) + color(blue)(1)) = (-a)^2`