Question

(3х+1)(9х^2-3х+1)-(9х^2+2)(3х-2)=16х^2+1

Answer 1

$(3x+1)(9x^2-3x+1)-(9x^2+2)(3x-2)=16x^2+1\\27x^3-9x^2+3x+9x^2-3x+1-27x^3+18x^2-6x+4=16x^2+1\\18x^2-6x+5=16x^2+1\\2x^2-6x+4=0\;\;\div2\\x^2-3x+2=0\\D=9-4\cdot2=1\\x_{1,2}=\frac{3\pm1}2\\x_1=1\\x_2=2$