Question

1. Calculati : a) (x-1)²...
b) (x-4)(x+4)..
c) (3x-2)²....
d) (2x²+x+1)²

Answer 1

Răspuns:

Explicație pas cu pas:

a)  ( x - 1 )² = x² - 2 x + 1 → aplic formula (a-b)² = a²- 2 ab + b²

b) ( x-4)(x+4) = x² - 16  →aplic formula (a-b)(a+b) = a² - b²

c) (3x-2)² = 9 x² - 12 x + 4

   = (3x)² - 2 × 3 x × 2 + 2² = 9 x² - 12 x + 4

d) ( 2 x² + x + 1 )² =  4 x⁴ + 4 x³ + 5 x² + 2 x + 1

= ( 2 x² + x + 1 ) ( 2 x² + x + 1 ) =

= 4 x⁴ + 2 x³ + 2 x² + 2 x³ + x² + x + 2 x² + x + 1 =

= 4 x⁴ + 4 x³ + 5 x² + 2 x + 1