she bought 9 shirts and 4 pants.
9 + 4 = 13 total articles of clothing.
Let's create an equation to model the problem.
x = price of one shirt or one pants
13x + $6 = $71
Subtract $6 from both sides.
13x = $65
Divide both sides by 13
x = $5
Each shirt or pair of pants costs $5.
The correct answer is D.