WRITING ALGEBRAIC EXPRESSIONS

An algebraic expression is  a combination of numbers, variables, and mathematical operations like addition, subtraction, multiplication, and division. It's like a math sentence without an equal sign, using letters (variables) to represent unknown quantities

Multiplication and addition with algebraic expressions

In algebra, we don't use the multiply sign between pronumerals and numbers. For example; we do not write 5 x k, rather we write 5k. It is implied that the operation is multiplication. This could be the same for words like lots of or groups of - they all imply the operation of multiplication. 

We need to remember that when we are adding like terms, we are also using multiplicatives. For example; 3 lots of A is the same as A + A + A which equals 3A. 

SUBSTITUTION

Substitution means replacing a variable in an expression or equation with a specific value or another expression. This is often done to simplify expressions, solve equations, or evaluate the value of an expression for a given variable.