## How do you substitute values in algebraic expressions?

To substitute a number into an algebraic expression, all you need to do is re-write the expression in exactly the same way, except replacing the variable (letter) with the number. It always makes it clearer to put the number in brackets too. Then you can simplify your new expression and you have your answer!

**What is substituting into an expression?**

Substitution means putting numbers in place of letters to calculate the value of an expression .

### How do you translate an expression into an algebraic expression?

When translating phrases into algebraic expressions, you need to identify keywords and phrases which specifically refer to a mathematical operation (addition, subtraction, multiplication, and division). Usually, you can write out the algebraic expression of the verbal description in the order that it is said.

**What is an evaluating expression?**

To evaluate an algebraic expression means to find the value of the expression when the variable is replaced by a given number. To evaluate an expression, we substitute the given number for the variable in the expression and then simplify the expression using the order of operations.

#### Do you need parentheses when substituting?

If substituting one variable for another, then parentheses are never needed (the order of operations is clearly identical before and after). If substituting a whole number, then only the situation of juxtaposed numbers after the coefficient can apply.

**How do you substitute expressions?**

To use the substitution method, use one equation to find an expression for one of the variables in terms of the other variable. Then substitute that expression in place of that variable in the second equation. You can then solve this equation as it will now have only one variable.

## How do you write and evaluate algebraic expressions?

To evaluate an algebraic expression, you have to substitute a number for each variable and perform the arithmetic operations. In the example above, the variable x is equal to 6 since 6 + 6 = 12. If we know the value of our variables, we can replace the variables with their values and then evaluate the expression.

**Does adding parentheses change the value of the expression?**

As you can see, adding parentheses can really change the outcome of our expression! Since this first equation tells us the value of x, we can actually substitute this for x in the second equation using parentheses. So now, instead of 3x−7y, we have 3(2y–3)–7y=−14.

### What is this algebraic expression worksheet?

This worksheet also features negative numbers, brackets and powers. A worksheet for pupils to practise creating an algebraic expression and then substituting into it. Can be used as a standalone worksheet or as an extension task for the worksheet above.

**How to simplify algebraic expressions?**

20 Simplifying Algebraic Expressions by Distributing and Combining Like Terms 1.a 3(x + 6y – 7) 1.b. -7(2x – 4) Distribute first…. then catch and combine like terms.

#### How do you use distributive property in algebraic expressions?

13 Use the Distributive Property to expand each expression. Ex. -4(2n + 5) a. 3(4x + 2) b. -5( y – 7) c. -2(n + 9) d. 3(-1 – 5c) e. x(3 + 4y) f. -1(a – 1) g. ½(4x – 6) h. − 1 4 (8x + 12) i. 3 4 (8x – 12) x P 14 Expand the expressions that require the distributive property.

**What is a substitute worksheet?**

A worksheet for practising substituting numbers into an algebraic expression. This worksheet also features negative numbers, brackets and powers. A worksheet for pupils to practise creating an algebraic expression and then substituting into it. Can be used as a standalone worksheet or as an extension task for the worksheet above.