Answer: 58.42
Formula: Multiply the length value by 2.54
23×2.54
=58.42
12 Inches = 30.48 Centimetres
So start with the top one and end w the bottom
You can use either of these, depending on your teacher.
2.e+14
2.0*10^14
3/4 - 3/5
common denominator is 20
15/20 - 12/20 = 3/20
3/20 is your answer
multiply the opposite denominator with current numerator to get your new numerator number
hope this helps