Question

(x+3)^2-(x-√5)^2+3 va rog foarte repede

Answer 1

Răspuns:

Explicație pas cu pas:

=x²+6x+9-x²+2√5 x -5 +3=2(3+√5)x+7

Answer 2

$(x+3)^2-(x-\sqrt 5)^2+3 =\\ \\ \left[(x+3)-(x-\sqrt{5})\right]\cdot \left[(x+3)+(x-\sqrt{5})\right]+3 \\\ \\ = (x+3-x+\sqrt{5})(x+3+x-\sqrt{5})+3 \\ \\ =(3+\sqrt{5})(2x+3-\sqrt{5})+3 \\ \\ =2x(3+\sqrt{5})+(3+\sqrt{5})(3-\sqrt{5})+3\\ \\ = 6x+2\sqrt 5 x+9-5+3\\ \\ =(6+2\sqrt{5})x+7$