Explanation:
10. 2(x^2 + 6x + 5): factor out 2
2(x + 5)(x + 1)
After factoring out the 2, find the 2 numbers that multiply to get 5 and add to 6
5 + 1 = 6
5*1 = 5
x^2 = x * x
11. (x - 10)(x - 4)
12. (a - 8b)(a + 8b)
a^2 + 8ab - 8ab - 64b^2
First: a*a = a^2
Outside 8b*a = 8ab
Inside: -8b*a = -8ab
Last: -8b*8b= -64b^2