How many 3 digit numerical passowords are there if a digit can be repeated?
1 answer:
You might be interested in
Hey there :)
We have two equations:
3a + 2b = 7
2a + 2b = 9
We need to solve simultaneously to find the values of a and b
eq.1 3a + 2b = 7
eq.2 ( 2a + 2b = 9 ) x -1 ) multiply by -1 to cancel 2b
3a + 2b = 7
- 2a - 2b = -9 ( Add both together )
-------------------
a = - 2
Substitute the value you found for a in a in order to find b
3( - 2 ) + 2b = 7 2( - 2 ) + 2b = 9
- 6 + 2b = 7 OR - 4 + 2b = 9
2b = 13 2b = 13
b =
b =
We have two equations:
3a + 2b = 7
2a + 2b = 9
We need to solve simultaneously to find the values of a and b
eq.1 3a + 2b = 7
eq.2 ( 2a + 2b = 9 ) x -1 ) multiply by -1 to cancel 2b
3a + 2b = 7
- 2a - 2b = -9 ( Add both together )
-------------------
a = - 2
Substitute the value you found for a in a in order to find b
3( - 2 ) + 2b = 7 2( - 2 ) + 2b = 9
- 6 + 2b = 7 OR - 4 + 2b = 9
2b = 13 2b = 13
b =