Question

(2x+3)^2-(2x-3)(2x+3)+ 2(x-1)^2
Va rog !

Answer 1

... = 4x²+12x+9 - (4x² - 9) +2(x² - 2x +1) =
  
    = 4x² + 12x + 9 - 4x² + 9 + 2x² - 4x + 2 =

    = 2x² + 8x + 20

Answer 2

(2x + 3)² + 2(x-1)² + -(2x)² - 2x•3+3•2x+9
(2x)²+2•2x•3+3²-2²x²+2(x²+2x•(-1)+(-1)²) - 6x + 6x + 9
(2x+3)² + 2(x-1)² + -(2x)² - 2x•3+3•2x+9
2(1+x²+(-2)x) - 4x² + 9 + 2² x² + 12x + 9
4x² + 2(x²-2x+1)-4x²+12x+18
(2x)²+2•2x•3+3²-2²x²+2(x²+2x•(-1)²)-6x + 6x + 9
2x² - 2•2x + 2 + 12x + 18
2x² - 4x + 12x + 20
(2x+3)² + 2(x-1)² + -(2x)² - 2x•3 + 3•2x + 9
= 2x² + 8x + 20.