" 2."(n)/(2);(3n+5n)/(4)=21

Simplify: find the value of n (n)/(2)-(3n)/(4)+(5n)/(6)=21

Solve the linear equations.(n)/(2)-(3n)/(4)+(5n)/(6)=21

n/2 - (3n)/4 +(5n)/6 = 21

The sum of the series 1+4+3+6+5+8+ upto n term when n is an even number (n^(2)+n)/(4) 2.(n^(2)+3n)/(2) 3.(n^(2)+1)/(4) 4.(n(n-1))/(4)(n^(2)+3n)/(4)

Prove that 5^(n) (1+(n)/(5) +(n(n-1))/(5*10) +(n(n-1)(n-2))/(5*10*15)+…oo)=3^(n) (1+(n)/(2)+(n(n+1))/(2*4)+(n(n+1)(n+2))/(2*4*6)+…oo)

Prove that 7^(n)(1+(n)/(7)+(n(n-1))/(7.14)+(n(n-1)(n-2))/(7.14.21)...)=4^(n)(1+(n)/(2)+(n(n+1))/(2.4)+(n(n+1)(n+2))/(2.4.6)...)

If .^(2n)C_(4): .^(n)C_(3)=21:1 , then find the value of n.