Answer
100 cards
Work Step by Step
The expression for pristine printing cards is $15+0.10x$.
The expression for printing place cards is $10+0.15x$.
Set the expressions equal to each other:
$15+0.1x=10+0.15x$ (subtract 0.1 from both sides)
$15=10+0.05x$ (subtract 10 from from both sides)
$5=0.05x$ (divide both sides by 0.05 to isolate the variables)
$\frac{5}{0.05}=x$ (divide)
$x=100$
