Evaluating a variable expression 2

In summary, the conversation discusses how to evaluate a variable expression when given specific values for the variables. The steps involve substituting the values into the expression and solving it using arithmetic rules. It is also recommended to use descriptive titles for topics and to show work to receive the best help possible.
  • #1
rodgerst414
8
0
Evaluate the variable expression when a=3,b=1 and c=-2

b^2-4ac. This is new to me so please explain how to do this.
 
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  • #2
Okay, what you want to do is let the 3 variables take on the given values, and put these into the expression you are asked to evaluate:

This would give us:

$(1)^2-4(3)(-2)$

Now, can you compute this expression following the rules of arithmetic?
 
  • #3
For future topics, I highly recommend using a title that briefly describes the problem. For example, a good title for this topic is "Evaluating a variable expression". This let's our helpers know exactly what kind of problem is being discussed.
 
  • #4
MarkFL said:
For future topics, I highly recommend using a title that briefly describes the problem. For example, a good title for this topic is "Evaluating a variable expression". This let's our helpers know exactly what kind of problem is being discussed.
how do you make more posts.
 
  • #5
rodgerst414 said:
how do you make more posts.
Thank you for helping me.
 
  • #6
Follow the same procedure you used to create this topic. You are welcome to create as many topics as there are problems with which you need help.

We do request that as you learn from the help given in previous problems that you apply this to subsequent problems, and show what you think you should do. This allows us to see how you are progressing, and what things may need to be made more clear. (Smile)

All of the staff and helpers (official or otherwise) are glad to help others gain a better understanding of mathematics.
 
  • #7
By the way, were you able to complete the problem you posted in this topic? Can you show your work? Giving feedback is a great way to get the best help possible. This way we can ensure you are doing it correctly, and if not, we will be able to tell you why.
 

FAQ: Evaluating a variable expression 2

What is a variable expression?

A variable expression is a mathematical phrase that contains one or more variables, which are symbols that represent unknown values. These expressions can include numbers, operations, and variables, and can be evaluated to determine their value.

How do you evaluate a variable expression?

To evaluate a variable expression, you need to substitute the values of the variables with known numbers, and then follow the order of operations. This will result in a numerical value for the expression.

Can a variable expression have more than one variable?

Yes, a variable expression can have more than one variable. For example, 2x + 3y is a variable expression with two variables, x and y.

What is the difference between a variable expression and an algebraic expression?

A variable expression contains one or more variables, while an algebraic expression contains variables, constants, and operations. In other words, an algebraic expression is a more general term that includes variable expressions.

How can variable expressions be used in real-life situations?

Variable expressions can be used to represent and solve real-life problems. For example, if you are trying to calculate the total cost of a purchase with tax, you can use a variable expression to represent the cost of the item and the tax rate, and then evaluate the expression to find the total cost.

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