x - 4.
x^2 + 5x - 36 = (x - 4) (x + 9)
x^2 - 9x + 20 = (x - 4) (x - 5)
(x + 10) and (x + 4) are both factors
x2-12x+35 = (x-5)(x-7)
(y + 3z)(y^2 - 3yz + 9z^2)
You didn't bother to list the binomials to choose from, but the two binomial factors of x2 + 6x - 40 are (x + 10) and (x - 4)
3x2 + 6x is ONE expression. A common factor is a factor that is COMMON to two (or more) expressions - not just one. An alternative answer: 3x can be factored out of both of those.
(x + 10) and (x + 4) are both factors
4y - 3
x + 4
The factors are (x + 6) and (x - 3)
(x - 1)(3x + 5)
(x - 14)(x - 2)
(x - 5)(x - 8)
Remember to factor out the GCF of the coefficients if there is one. A perfect square binomial will always follow the pattern a squared plus or minus 2ab plus b squared. If it's plus 2ab, that factors to (a + b)(a + b) If it's minus 2ab, that factors to (a - b)(a - b)
(y + 6)(y - 3)
If that's 3x2 + 7x + 2, the answer is (x + 2)(3x + 1)
v2+36v+99 = (v+3)(v+33) when factored
It is: (c-4)(c-8) when factored