(16x^2-9/4x+3)-4x b^8*b^12*b^17 (4^9)^8:4^73 (2x)^4*x^-8/x^-6*2x^2

Упростим выражения:

1) ((16 * x^2 - 9)/(4 * x + 3)) - 4 * x = ((4 * x)^2 - 3^2)/(4 * x + 3) - 4 * x = (4 * x - 3) * (4 * x + 3)/(4 * x + 3) - 4 * x = (4 * x - 3) * 1/1 - 4 * x = 4 * x - 3 - 4 * x = 0 - 3 = -3; 

2) b^8 * b^12 * b^17 = b^(8 + 12 + 17) = b^(20 + 17) = b^37; 

3) (4^9)^8 : 4^73 = 4^(9 * 8)/4^73 = 4^72/4^73 = 4^(72 - 73) = 4^(-1) = 1/4 = 0.25; 

4)  (2 * x)^4 * x^(-8)/(x^(-6) * 2 * x^2) = 2^4 * x^4 * x^(-8)/(2 * x^(-6) * x^2) = 16 * x^(4 - 8)/(2 * x^(-6 + 2)) = 16 * x^(-4)/(2 * x^(-4)) = 16/2 * x^(-4 - (-4))  = 8 * x^0 = 8 * 1 = 8.