Question

the sum of three consecutive even numbers is 30. find the difference of the square of the extreme numbers  

Answer 1

let the no.s be x , x+2 and x+4
atq
x+(x+2) +(x+4)=30
x+x+x+2+4=30
3x+6=30
3x= 24
x= 8
even numbers are 8 , 10, and 12
extreme numbers are 8&12
144-64 =80

Answer 2

By the method of trial and error, I found that the numbers are 8,10 and 12.
mathematically if you consider the numbers to be x, x+2,x+4 and equate them to 30 you'll get the same answer.
extreme numbers are 8 and 12
the squares of 12 and 8 are 144 and 64.
Difference is 144-64=80