Question

3. Efectuaţi, folosind formulele de calcul prescurtat: a) (2x + 1)la patrat - (3x + 4)la patrat + (3x + 2)la patrat

nu inteleg nmk :(​

Answer 1

Răspuns:

Explicație pas cu pas:

a^2 - b^2 = (a -b)(a +b)

(2x + 1)^2 - (3x + 4)^2 =

((2x + 1)- (3x + 4))((2x + 1) + (3x + 4)) =

(2x +1 -3x -4)(2x +1 +3x +4) =

(-x -3)(5x +5) = -5(x+1)(x+1) = -5(x+1)^2 = -(√5(x+1))^2

(3x + 2)^2 -(√5(x+1))^2=

(3x + 2) -√5(x+1))(3x + 2) +√5(x+1 =

(3x +2 -√5x -√5)(3x +2 +√5x +√5)