Answer is 220
i) 1 – 3 + 4 = 100,
If we solve it we get;
1 – 3 + 4 = -2+4 = 2
So 2 = 100.
ii) 4 – 6 + 9 = 999
we get 7 = 999
iii) 2 – 6 + 7 = 879
We get 3 = 879
Now we need to solve the last equation for which we need the answer;
So 3 -3 +6 = 6
we need to find the value of 6 which from above (i) + (ii) – (iii);
So 100 + 999 – 879 = 220
So 6 = 220