Answer:
x=5
y=1
Step-by-step explanation:
The substitution method is considered easier because of its simplification.
2x-3y=7 (1)
x+2y=7 (2)
considering equation (2),
x = 7 - 2y (3)
using the value of "x" in (1)
2 (7-2y) - 3y=7
14 - 4y- 3y = 7
14 - 7y = 7
7y = 14 - 7
7y = 7
y = 1 (4)
substituting this value of "y" in (3)
x = 7- 2(1)
x = 5
If b is in the first position then c can be in any 1 of the remaining 6 positions.
If we start with ab then the letter c can be in any one of 5 positions and if we have aab there are 4 possible positions for c and so on.
So the total number of possible sequences where b comes first = 6+5+4+3+2+1 = 21.
The same argument applies when c comes before b so that gives us 21 ways also.
So the answer is 2 *21 = 42 different sequences.
A more direct way of doing this is to use factorials:-
answer = 7! / 5! = 7 * 6 = 42.
( We divide by 5! because of the 5 a's.)
Answer:
21
Step-by-step explanation:
Idk
