a+b=9 a+c=4 b+c=5 . Find a+b+c.

(A) 4 (B) 5 (C) 7 (D) 8 (E) 9

show your work please.
thanks!

(E) 9

Step-by-step explanation:

A= 4

B= 5

C= 0

a+b+c= 4+5+0= 9

a+b=9= 4+5=9

a+c=4= 4+0=4

b+c=5= 5+0= 5

(n^3 - n)

= n(n-1)(n+1)

since it is divisible by 3 and 2 ,because it is a multiple 3 consecutive number

if, n-1 is odd then n+1 is also odd, then it is a multiple of 9

but if, n-1 is even then n+1 is also even, then it is a multiple of 4

so, largest multiple = max(9*2, 4*3) = max(18, 12) = 18

what is the original number? you forgot to add it.