To represent Jonas's savings in an equation of the form \( y = mx + b \), we can identify the components as follows:
- \( y \) will represent the total amount of money in Jonas's savings account after \( x \) weeks.
- The slope \( m \) is the rate at which he adds money each week, which is $3. So, \( m = 3 \).
- The y-intercept \( b \) is the initial amount of money Jonas has, which is $50. So, \( b = 50 \).
Putting these together, the equation that represents the relationship between the amount of money \( y \) and the number of weeks \( x \) is:
\[ y = 3x + 50 \]