If there is 2 digits and 7 numbers the combos would be:
1,1 2,1 3,1 4,1 5,1 6,1 7,1
1,2 2,2 3,2 4,2 5,2 6,2 7,2
1,3 2,3 3,3 4,3 5,3 6,3 7,3
1,4 2,4 3,4 4,4 5,4 6,4 7,4
1,5 2,5 3,5 4,5 5,5 6,5 7,5
1,6 2,6 3,6 4,6 5,6 6,6 7,6
1,7 2,7 3,7 4,7 5,7 6,7 7,7
Therefore there are 49 possible combinations :)
There is no b unfortunately
Find inverse of x+a
interchAnge
Inverse is
Now
- x-a=cx-d
- x-cx=a-d
- x(1-c)=a-d
- x=a-d/1-c
So
You can have any number according to this but
- c must not be 1
- a and d must not be equal .
- All three should belongs to integers set
Note:-
As there is no b given in question (May be missed in typing) Part-2 's equation can't be executed and part 3 also
I searched up it said 1,295,996,310