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Evaluating expressions review

An algebraic expression like 3x can be evaluated for any value of x. Say x=4, then 3x = 3*4 = 12. In this article, we review how to evaluate algebraic expressions.

What does it mean to evaluate an algebraic expression?

An algebraic expression like 2x+3 can be evaluated by substituting a value for x. For example, if x=4 then:
2x+3=24+3=8+3=11
We can also evaluate more complicated expressions that have more than one variable. For example, we can evaluate 10+2p3r when p=4 and r=5:
10+2p3r=10+2435=10+815=3
Want to learn more about evaluating expressions? Check out this video. And here's a word problem video if you're curious how this concept might apply to the real world.

Practice

Problem 1
Evaluate the expression 7+4b when b=3.
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi

Want more practice like this? Check out this basic exercise and this more advanced exercise.