Question

(3х-1)(3х+1)+(3х+1)2.

Answer 1

(3х-1)(3х+1)+(3х+1)^2=(3x)^2-1^2+(9x^2+1+6x)=9x^2-1+9x^2+1+6x=18x^2+6x

Answer 2

(3х-1)(3х+1) + (3х+1)² = 9х² -  1  + 9х² + 6х + 1 =  18х²  +  6х