Find the value of ` x^2 - 9 `

Find the value of : 3x^(2)+9x^(2)-x+8 where x=-2

If 3x-7y=10\ and x y=-1, find the value of 9x^2+49 y^2

If 3x + 4y= 16 and xy= 4 , find the value of 9x^(2) + 16y^(2)

Find the value of x if: (-9)/(16)xx(4)/(3)=(x)/(2)

If x= -5 + sqrt(-16) , find the value of x^(4) + 9x^(3) + 35x^(2)-x + 4

If 3^(3x)=(9)/(3^(x)) , find the value of x .

Given ((8)/(27))^(x- 1) = ((9)/(4))^(2x+ 1) , find the value of x .

Find the value of x and y when 3x+y=3 9x-3y=9

(a) Find the value of x if 1 + 6 + 11 + ... + x = 189. (b) Find the value of x if 3 + 6 + 9 + ... + 96 = x.

If 2x+3y=8 and x y=2 , find the value of 4x^2+9y^2