" If "D_(x)=20" and "D=5," then "x=

For simultaneous equations in x and y , if D_(x)=25 , D_(y)=50 and D=5 , then what is the value of x ?

If D_(x) = 25, D = 5 are the values of the determinants for certain simultaneous equations in x and y , find x.

D={x:x=2n-1<20 and n in N}

If log_(10)x+log_(10)5=2, then x equals a.15b20c.25d.100

For certain simultaneous equations, if (i) D=-5 , D_(x)=15 , D_(y)=-10 (ii) D=4 , D_(x)=2 , D_(y)=8 . Find the values of x and y .

If x^3-1/(x^3)=14 , then x-1/x=? (a)5 (b) 4 (d) 3 (d) 2

If (c)/(d)-(a)/(b)=x, a=2c, and b=5d , what is the value of (c)/(d) in terms of x?

The standard deviation of n observations x_(1), x_(2), …, x_(n) is 2. If sum_(i=1)^(n)x_(i)=20 and sum_(i=1)^(n)x_(i)""^(2)=100 , then n is : a) 10 or 20 b) 5 or 10 c)5 or 20 d) 5 or 15