Answer and explanation:
Katherine is 6 inches taller --> + 6
Katherine is 48 inches --> 48
Put those two numbers together
48 - 6 <-- this would be the equation to represent Emily's height
48 is Katherine's original height and the -6 would be how much taller Emily is.
Since Katherine is taller than Emily by 6 inches, that would make Emily -6 inches taller than Katherine.