Answer:
x=2/5, y=-3. (2/5, -3).
Step-by-step explanation:
10x+3y=-5
-5x-4y=10
----------------
10x+3y=-5
2(-5x-4y)=2(10)
-------------------------
10x+3y=-5
-10x-8y=20
-------------------
-5y=15
y=15/-5
y=-3
10x+3(-3)=-5
10x-9=-5
10x=-5+9
10x=4
x=4/10=2/5
In general, nCr = n! / r! (n-r)!
Here, 7C3 = 7! / 3!(7-3)!
=7 x 6 x 5 x 4 x 3 x 2 x 1 /3 x 2 x 1 ( 4 x 3 x 2 x 1)
=7x6x5x4 / 4x3x2
=7x5x6x4 / 24
=35x24 / 24
=35
Answer:
think its A
Step-by-step explanation: