LoryLullic

% increase$=\frac{(\text{final value minus initial value})}{\text{absolute value of the initial value}}\cdot 100$ And in this example: $\frac{77-50=27}{\text{initial value}=50}=\frac{27}{50} \cdot100$   

I'll leave it up to you to simplify $\downarrow$ Hope this helps!

                                 Answer=$\frac{27}{50} \cdot 100$

In three years, Sandra will be 3x and Jason will be x. We also know that x+18=3x. Using these equations, x=9, and 3x=27. That means, in three years, Sandra will be 27. Two years ago, Sandra was 22 years old. Hope this helps!