Question

1. Daca descompunem in factori $x^{2} + 7x + 10$ , obtinem.........
2. Dintr-o bucata de sarma lunga de 180 cm putem construii un tetraedru regulat cu latura de ........ cm.
3. Simplificati raportul $\frac{ x^{3} + x^{2} -9x-9 }{ x^{3} - 3 x^{2} - x+3}$, unde x = R -{-1;1;3}.

Answer 1

1) =x²+2x+5x+10=x(x+2)+5(x+2)=(x+5)(x+2)

2) un tetraedru are 6 muchii, 180:6=30 cm latura

3)=$\frac{x^2(x+1)-9(x+1)}{x^2(x-3)-(x-3)}= \frac{(x^2-9)(x+1)}{(x^2-1)(x-3)}= \frac{(x-3)(x+3)(x+1)}{(x^2-1)(x-3)}(simpl.cu(x-3))=$
$= \frac{(x+3)(x+1)}{x^2-1}$