Answer:
NM = 8
Step-by-step explanation:
Given rectangle JKLM
JN = x + 3 and JL = 3x + 1
JN = 1/2JL as diagonals bisect each other and N is the midpoint of JL.
Substitute and solve for x:
x + 3 = 1/2(3x + 1)
2x + 6 = 3x + 1
3x - 2x = 6 - 1
x = 5
Find JN
JN = 5 + 3 = 8
Looking at the options, we see that
NM = JN = 8
Correct option is A
Answer:
C
Step-by-step explanation:
The surface area of the box will be 112 in²
Explanation
According to the given diagram, the shape of the box is Right Rectangular prism.
The formula for the surface area is :
, where
length,
width and
height of the rectangular prism
Given in the diagram that, 
So, plugging the values into the formula...

So, the surface area of the box is 112 in²