a + b + c + d = d + e + f + g = g + h + i = 17
Means, ( a + b + c + d )+ (d +e + f + g )+ (g +h + i ) = 17 +17+17 = 17 x 3 = 51
a + b + c + d + e + f + g + h + i +( d + g ) = 51
Step 2.
But 'a' to ' i ' takes values only from 1 to 9
So a + b + c + d + e + f + g + h + i = sum of the numbers from 1 to 9 = 45
Step 3.
From step 1 and step 2
d + g = 51 - 45 = 6
possible values of d & g are (1, 5), ( 5,1 ), (2,4) & (4, 2 )
( 2, 4 ) & ( 4 , 2 ) are not possible as "a = 4 "
We have to try with other values (1, 5 ) & ( 5 , 1 )
Step 4.
When d = 1 and g = 5
1. a + b + c + d = 4 + b +c + 1 = 17
b + c = 12 ; only possible values of b & c are ( 9, 3 ) or ( 3, 9 )
2. d + e + f + g = 1 + e + f + 5 = 17
e + f = 17 - 6 = 11
possible combinations for 11 are ( 2,9 ) ; ( 3,8 ) ; (4,7 ) & ( 5,6 )
b & c takes values 3 & 9 g = 5 (assumed) and a = 4 (given).
So, d = 1 & g = 5 is not the solution.
Case 2.
When d = 5 and g = 1
1. a + b + c + d = 4 + b + c + 5 = 17
b + c = 17 - 9 = 8
only possible combination is 2 & 6
a + b + c + d = 4 + ( 2 + 6 ) + 5 = 17
2. d + e + f + g = 5 + e + f + 1 = 17
e + f = 17 - 6 = 11
The only possible value is 3 & 8
d + e + f + g = 5 + ( 3 + 8 ) + 1 = 17
g + h + i = 1 + h + i = 17
h + i = 17 - 1 = 16
The only possible value for h & i are 7 & 9
g + ( h+ i ) = 1 + ( 7 + 9 ) + 17
So the values of d = 5 & g = 1