15. \( c+\frac{5}{9}=\frac{8}{9} \), add / subtract, \( c=\square \)

To solve for \( c \) in the equation \( c + \frac{5}{9} = \frac{8}{9} \), you need to isolate \( c \). Start by subtracting \( \frac{5}{9} \) from both sides of the equation. This gives you: \[ c = \frac{8}{9} - \frac{5}{9} \] Calculating that, you get: \[ c = \frac{8 - 5}{9} = \frac{3}{9} = \frac{1}{3} \] So, \( c = \frac{1}{3} \). --- Mathematics has a rich history, with equations like this one dating back thousands of years. Ancient Babylonians were among the first to develop algebraic equations, using base 60 for their calculations, which still influences our time and angle measurements today! Understanding how to manipulate equations is vital not just in math classes, but also in everyday life. Need to compare prices or ingredients in recipes? The same addition and subtraction principles apply. Being comfortable with equations can help you make better decisions and solve problems efficiently!