Try It For Yourself – Substitution vs. Combination

Let’s try another one. Would combination or substitution be easier with the following system of equations?

Click either Combination or Substitution and then click Continue.

Combination    Substitution

The second equation allows you to find j in terms of k very easily. You’ll get a fairly simple , which will make things cancel beautifully in the first equation. Substitution works much quicker than combination here. If you combined, you’d have to make fractions and integers cancel out — too much room for error to make that approach a good strategy.