Explicație pas cu pas:
Formule:
- (a + b)² = a² + 2ab + b²
- a² - b² = (a - b) • (a + b)
4(x - 2)² + 20(x - 2) + 25 - (x + 1)² =
[2•(x - 2)]² +20•(x - 2) + 5² - (x + 1)² =
[2•(x - 2)]² + 2•5•2•(x - 2) + 5² - (x + 1)² =
[2•(x - 2) + 5]² - (x + 1)² =
(2x - 4 + 5)² - (x + 1)² =
(2x + 1)² - (x + 1)² =
[(2x + 1) - (x + 1)] • [(2x + 1) + (x + 1)] =
(2x + 1 - x -1) • (2x + 1 + x + 1) =
(2x - x)•(3x + 2) =
x•(3x + 2)
#copaceibrainly
