Since the given two angles are complementary, then
The sum of their measures is 90 degrees
Add the two angles and equate their sum by 90 degrees
[tex]3y-4+73^{\circ}=90^{\circ}[/tex]
Add the like terms on the left side
[tex]\begin{gathered} 3y+(-4+73)=90 \\ 3y+69=90 \end{gathered}[/tex]
Subtract 69 from both sides
[tex]\begin{gathered} 3y+69-69=90-69 \\ 3y=21 \end{gathered}[/tex]
Divide each side by 3
[tex]\begin{gathered} \frac{3y}{3}=\frac{21}{3} \\ y=7 \end{gathered}[/tex]
The value of y is 7
