Find the value of `x` : `(2x)/(5)=(8)/(7)`

Find the value of 3x^2-5x+8 for x=3

Find the value of x , if 5^(x-3). 3^(2x-8)=225

Find the value of x , if 5^(x-3)\ 3^(2x-8)=225

Find the value of x , if : (i) (2x + 3) : (5x - 38) is the duplicate ratio of sqrt(5) : sqrt(6). (ii) (2x + 1) : (3x + 13) is the sub-duplicate ratia of 9 : 25 . (iii) (3x - 7) : (4x + 3) is the sub-triplicate ratio of 8 : 27 .

If x^(2) + (1)/(x^(2))= 7 and x ne 0 , find the value of : 7x^(3) + 8x- (7)/(x^(3))- (8)/(x)

Find the value of : 2x^(4)-5x^(3)+7x-3 where x=-3

Solve : (2x)/(3)-(x-1)/(6)+(7x-1)/(4)=2(1)/(6) . Hence, find the value of 'a', if (1)/(a)+5x=8 .

If x=5, find the value of : 6-7x^(2)

Find the value of x for which (8x+4),\ (6x-2) and (2x+7) are in A.P.

Find the value of : 4x^(3)-5x^(2)-6x+7 when x=3