How do I evaluate an expression?

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.

What is evaluate expression?

Evaluate Algebraic Expressions. 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.

How do you evaluate an expression with one variable?

Evaluating an Expression with one Variable. A mathematical expression can have a variable as part of the expression. If x=3, the expression 7x + 4 becomes 7 * 3 + 4 which is equal to 21 + 4 or 25. To evaluate an expression with a variable, simply substitute the value of the variable into the expression and simplify.

How do you evaluate an expression with two variables?

A mathematical expression can have variables as part of the expression. If x=3, and y=5, the expression 7x + y – 4 becomes 7 * 3 +5 – 4 which is equal to 21 + 5 – 4 or 22. To evaluate an expression with two or more variables, substitute the value of the variables into the expression and simplify.

How do you simplify expressions?

To simplify any algebraic expression, the following are the basic rules and steps:

Remove any grouping symbol such as brackets and parentheses by multiplying factors.
Use the exponent rule to remove grouping if the terms are containing exponents.
Combine the like terms by addition or subtraction.
Combine the constants.

What is an example of simplify?

Example 1: Simplify: 5(7y+2) 5 ( 7 y + 2 ) . Solution: Multiply 5 times each term inside the parentheses. Example 2: Simplify: −3(2×2+5x+1) − 3 ( 2 x 2 + 5 x + 1 ) . Because multiplication is commutative, we can also write the distributive property in the following manner: (b+c)a=ba+ca ( b + c ) a = b a + c a .

How do you solve algebraic expressions?

Here’s how you would do it:

(x + 3)/6 = 2/3. First, cross multiply to get rid of the fraction.
(x + 3) x 3 = 2 x 6 =
3x + 9 = 12. Now, combine like terms.
3x + 9 – 9 = 12 – 9 =
3x = 3. Isolate the variable, x, by dividing both sides by 3 and you’ve got your answer.
3x/3 = 3/3 =
x =1.

What are the 4 steps to solving an equation?

We have 4 ways of solving one-step equations: Adding, Substracting, multiplication and division.

Why should we solve for a variable?

you define it, and it lets you know how to properly write the equation. Skylar, If you want to solve for the unknowns using mathematical equations it is necessary to define the unknown variables i.e. what they represent in the real world so that the known relationships can be expressed in equation form.

How do you multiply both sides?

Basically you just multiply the left part (everything before the equals sign) by something, and then do the same to the right side, and put the results together again with an equals sign. For example, multiply x = 15 by 3. First the left side: x * 3 = 3x.

Why do we solve equations?

Even if they can, it is often simpler and faster to use a computational method to find a numerical solution. The real power of equations is that they provide a very precise way to describe various features of the world. (That is why a solution to an equation can be useful, when one can be found. )

How do you do variables on both sides?

Solving Equations with a Variable on Both Sides. After simplifying, the first step in solving an equation with a variable on both sides is to get the variable on one side. This is done by reversing the addition or subtraction of one of the terms with the variable.

How do you do multi step equations with variables on both sides?

Multi-step Equation Example 1

First, let’s subtract one from both sides of the equation: 5x = 2x + 9.
Next, subtract 2x from both sides of the equation. The scale is still balanced: 3x = 9.
To isolate the x, use the opposite of multiplication. Divide by 3 on both sides of the equation.

How do you solve multi-step problems?

Here are steps to solving a multi-step problem: Step 1: Circle and underline. Circle only the necessary information and underline what ultimately needs to be figured out. Step 2: Figure out the first step/problem in the paragraph and solve it. Last step: Find the answer by using the information from Steps 1 and 2.

How do you solve multi-step inequalities?

The general procedure for solving multi-step inequalities is as follows.

Clear parentheses on both sides of the inequality and collect like terms.
Add or subtract terms so the variable is on one side and the constant is on the other side of the inequality sign.

What is the first step in solving 5 2x 8x 3?

The first step on solving 5 – 2x < 8x – 3 would be 5 < 10x – 3.

What is the first step in solving inequality?

To solve an inequality use the following steps:

Step 1 Eliminate fractions by multiplying all terms by the least common denominator of all fractions.
Step 2 Simplify by combining like terms on each side of the inequality.
Step 3 Add or subtract quantities to obtain the unknown on one side and the numbers on the other.

How do we find out if a value is a solution?

If the numbers you get from evaluating the two expressions are the same, then the given value is a solution of the equation (makes the equation true). If the numbers don’t match, the given value is not a solution of the equation (makes the equation false).

How do you solve and inequality?

To solve a compound inequality, first separate it into two inequalities. Determine whether the answer should be a union of sets (“or”) or an intersection of sets (“and”). Then, solve both inequalities and graph.

What is the inequality formula?

In an equation the two expressions are deemed equal which is shown by the symbol =. Where as in an inequality the two expressions are not necessarily equal which is shown by the symbols: >, <, ≤ or ≥….Composing equations and inequalities.

x>y	x is greater than y
x≥y	x is greater than or equal to y
x	x is less than y
x≤y	x is less than or equal to y