Factor a^2(a+1)+a(a+1)+3(a+1)

$a^{2} (a + 1) + a (a + 1) + 3 (a + 1)$

Factor $a + 1$ out of $a^{2} (a + 1)$ .

$(a + 1) a^{2} + a (a + 1) + 3 (a + 1)$

Factor $a + 1$ out of $a (a + 1)$ .

$(a + 1) a^{2} + (a + 1) a + 3 (a + 1)$

Factor $a + 1$ out of $3 (a + 1)$ .

$(a + 1) a^{2} + (a + 1) a + (a + 1) \cdot 3$

Factor $a + 1$ out of $(a + 1) a^{2} + (a + 1) a$ .

$(a + 1) (a^{2} + a) + (a + 1) \cdot 3$

Factor $a + 1$ out of $(a + 1) (a^{2} + a) + (a + 1) \cdot 3$ .

$(a + 1) (a^{2} + a + 3)$