#### Answer

$y=4$

#### Work Step by Step

By combining like terms and by using the properties of equality, the solution to the given equation, $
5y+3=2y+15
$, is
\begin{array}{l}\require{cancel}
5y-2y=15-3
\\\\
3y=12
\\\\
y=\dfrac{12}{3}
\\\\
y=4
.\end{array}
Checking:
\begin{array}{l}\require{cancel}
5(4)+3=2(4)+15
\\\\
20+3=8+15
\\\\
23=23
\text{ (TRUE)}
.\end{array}
Hence, $
y=4
$.