Kevin painted [tex]\frac{1}{9}[/tex] of the wall.
Solution:
Fraction of the wall painted by Elena = [tex]\frac{5}{9}[/tex]
Fraction of the wall painted by Matthew = [tex]\frac{3}{9}[/tex]
Fraction of the wall painted by Kevin = ?
Full wall can be taken as 1.
To find the wall painted by Kevin:
Rest of the wall = Full wall – painted by Elena – Painted by Matthew
[tex]$=1-\frac{5}{9}-\frac{3}{9}[/tex]
[tex]$=\frac{1}{1} -\frac{5}{9}-\frac{3}{9}[/tex]
To make the denominator same, multiply the numerator and denominator of the first term by 9.
[tex]$=\frac{9}{9} -\frac{5}{9}-\frac{3}{9}[/tex]
[tex]$=\frac{9-5-3}{9}[/tex]
[tex]$=\frac{1}{9}[/tex]
Rest of the wall = [tex]\frac{1}{9}[/tex]
Hence the kevin painted [tex]\frac{1}{9}[/tex] of the wall.