First find x and y.
Solve system of equations by elimination.
3x-y=3
+(-x+y=3)
---------------
2x=6
x=3
Now plug in x into one of the equations to find y.
-3+y=3
y=6
xy=3x6=18
Answer:
The answer for 3/7 x 28 is 12.
Step-by-step explanation:
To solve this problem, we make use of the formula of
combination.
nCr = n! / r! (n – r)!
where n is the total number of subject teachers and r is
the number of subjects r = 1
For the English class n = 3
3C1 = 3! / 1! (3 – 1)! = 3
For the Algebra class n = 4
4C1 = 4! / 1! (4 – 1)! = 4
For the Biology class n = 2
2C1 = 2! / 1! (2 – 1)! = 2
The total number of different schedules would be the
product of the three combinations:
total combinations possible = 3 * 4 * 2
total combinations possible = 24
