The computer understands the following instructions. Please enter one of the following instructions in the input boxes:

- Use law
*index*.

*index*is the index of a law. Example: Use law 2. - Replace
*variable*by*number*.

*variable*is the name of a variable.*number*is an integer. Example: Replace x by 2. - Replace
*variable*by*expression*.

*variable*is the name of a variable.*expression*is an algebraic expression. Example: Replace a by (x+y)*2. - Replace
*expression*with law*index*.

*index*is the index of a law.*expression*is an algebraic expression. Example: Replace a*c with law 6. - Remove parenthesis.
- Do the arithmetic.
- Use symmetric axiom of equality.

Meaning: If x=y then y=x, where x and y stand for real numbers.

Please use the **login: test (password: test)** unless you have a personal account.

Here is an example.

worksheet 8

worksheet 10

worksheet 13

worksheet 14

worksheet 15

worksheet 16