## Elementary Algebra

Let X represent the number we are looking for. 2.1% of what number means 2.1% $\times$ X Is 10.5 means =10.5 So, this question translates to: 2.1% $\times$ X = 10.5 0.021 $\times$ X = 10.5 Divide both sides by 0.021 X = 500