Question

E(x) =15x²-16x-15
Aratati ca : E(x) =(3x-5)(5x+3)

Answer 1

E(x) =15x²-16x-15

15x²-16x-15 = 0 => x₁ = [16+√(256+900)] /30 = (16+34)/30 = 50/30 = 5/3

x₂ = (16-34)/30 = -18/30 = -3/5  =>

E(x) =15x²-16x-15  = (3x-5)(5x+3)

Answer 2

E(x)=15x²-16x-15

E(x)=15x²+9x-25x-15

E(x)=3x•(5x+3)-5(5x+3)

E(x)=(5x+3)(3x-5)

Dacă vrei,inversezi rezultatul.