Answer:
9 inches wide
Step-by-step explanation:
What we know:
Cindy has a 3-inch by 4-inch picture.
She wants to enlarge that picture so the length is 12 inches.
It's 4 inches long in the original, and 12 inches in the scale.
Divide 12 by 4 to get a scale factor of 3.
Multiply 3 by 3 (essentially 3^2) to get 9 inches as the width.
