Identify whether four 𝑥 minus five
𝑦 is an expression, an equation, an identity, a formula, or an inequality.
Let’s take a look at what we have
here: four 𝑥 minus five 𝑦. If we were answering an algebraic
problem and we had this statement, four 𝑥 minus five 𝑦, we couldn’t do very much
with this. We might be able to collect any
like terms, but we couldn’t solve it. We can’t solve it because we’re
missing something. We’re missing an equals sign. What we have here with four 𝑥
minus five 𝑦 is two separate terms linked by the subtraction. The word that we use for this is an
If we look at an equation, we can
remember that this needs an equals to symbol, and so do identities and formulas. So straightaway, we could say that
four 𝑥 minus five 𝑦 is not an equation, an identity, or a formula. An inequality needs to have an
inequality symbol, for example, less than or greater than or equal to. So four 𝑥 minus five 𝑦 is not an
inequality. We can give our answer that four 𝑥
minus five 𝑦 is an expression.