If `20^(-x) = (1)/(7)`, then `(20)^(2x) =`

If (20^(-x)=1/7) then which of the following is the value of (20)^(2x) ?

If [(x,y^(3)),(2,0)]=[(1, 8),(2,0)] then [(x,y),(2,0)]^(-1)=

If (1+2x+3x^(2) )^(10) = a_(0) + a_(1) x + a_(2) x^(2) +…+a_(20) x^(20) , then

If (1 + x - 3x^(2))^(10) = a_(0) + a_(1)x + a_(2)x^(2) + ....... + a_(20)x^(20) , then a_(2) + a_(4) + a_(6) + ……. + a_(20) =

If A={:[(0,7),(0,0)]andf(x)=1+x+x^(2)+....+x^(20) then f(A) =