Show that nC6 = nC4, find n​

n = 10

Step-by-step explanation:

From the question,

nC6 = nC4

n!/6!(n-6)! = n!/4!(n-4)!

Simplifying n! out of the equation

⇒ 1/6!(n-6)!  = 1/4!(n-4)!

Crossmultiplying

4!(n-4)! = 6!(n-6)!

4!(n-4)! = 6×5×4!(n-6)!

(n-4)! = 30(n-6)!

(n-4)(n-5)(n-6)! = 30(n-6)!

⇒ (n-4)(n-5) = 30

n²-4n-5n+20 = 30

n²-9n+20-30

n²-9n-10 = 0

Solving the quadratic equation,

n-10n+n-10 = 0

(n-10n)+(n-10) = 0

n(n-10)+1(n-10) = 0

(n+1)(n-10) = 0

Either

n+1 = 0

n = -1

or

n-10 = 0

n = 10

n canot be a negative value,

Therefore, n = 10

fa tha first one you gonna add y to both sides

it look like this

x-y+y=6+y

x=y+6

therefore your answer is

x =y+6

fa tha second one

you gonna flip tha equation

it gonna look like x-4y=y

then add 4 to both sides

it gonna look like tha

x-4 +4 =y +4

so therefore tha answer is x=y+4

step-by-step explanation: