Generally divided into these four situations.

1, a negative number multiplied by an algebraic expression.

Such as: -2(6-x)=- 12+2x

-2(x-6)=-2x+ 12

2. Absolute value

/a- 1/+/a+3/

When a is greater than or equal to 1

The original formula =a- 1+a+3=2a+2.

Others can try it themselves.

3. Root number

It is greater than 0. Absolutely.

4, square, 4, 6. ...

Also greater than 0

Pure original, hope to adopt, thank you.