Answer:
Length of carrier A = 2096 feet
 Length of carrier B=2082 feet.
Explanation:
Given , two air craft carriers are A and B . The carrier A is longer than the carrier B in length.
Total length of two carriers =4178 feet
Difference of two carriers = 14 feet
Let
 Length of carrier A =x feet 
And 
 Legth of carrier B =y feet
According to question 
The I equation is 
x+y=4178 
The II equation is 
 x-y= 14
Substitution method: In this method step I : we find value of x or y from the equation I 
 Step II: put the value of x or y in II equation then we get the value of another varaiable x or y 
Step : Again put the obatined value of variable x or y from step II in equation I then we get value of other variable x or y .
By using substitution method ,
 we find value of x from equation I 
x= 4178-y
 Now, put the value of x in equation II then we get 
 4178-y-y=14
4178-2y=14
4178-14=2y
4164=2y

y= 2082 
 Again , put the value of y in equation I
2082 +x=4178
x= 4178-2082
x=2096
Hence, the length of carrier A = 2096 feet 
 The length of carrier B= 2082 feet