Question

What is the input value when the output value is 31.5?
HELP PLEASE ASAP

Answer 1

the answer is C, i’m a math teacher

Answer 2

The correct Answer is 9 my good sir ( or ma'am )

Step-by-step explanation:

Simple, just flip the equation around and change the multiplication sign to a division sign.

So basically with all planks filled in its 9 times 3.5 which is equal to 31.5

Brianliest? :/

Hope I helped