#### Answer

$x=1.5$

#### Work Step by Step

Let x be the unknown number. Convert each word phrase into its algebraic equivalent.
If you add a certain number to 3 $\ \ \longrightarrow$ $x+3$
the result is the same as if you had $\longrightarrow$ =
multiplied the number by 3 $\ \ \ \ \ \ \ \ \ \ \,\longrightarrow$ $3x$
Solve the equation.
$x+3=3x\longrightarrow$ subtract x from each side
$x+3-x=3x-x\longrightarrow$ subtract
$3=2x\longrightarrow$ divide each side by 2
$3\div2=2x\div2\longrightarrow$ divide
$1.5=x$