Question

Which of the binomials below is a factor of this trinomial?

x2 - 13x + 36

A. x - 6
B. x + 6
C. x + 9
D. x - 9

Answer 1

to find the factors you need to get 2 numbers a and b where ab = 36 and a + b = -13

Answer 2

check out the factors of 36

6 and 6
-6 and -6
-9 and -4
9 and 4

would one of these fit?

Answer 3

- they need to equal -13 when added

Answer 4

the the factor will be (x + a) where a is one of the numbers

Answer 5

a simple example would be
x^2 + 4x + 4

we see that 2*2 = 4 and 2 + 2 = 4, so the factors are
(x + 2)(x + 2)

Answer 6

but that doesnt make sense for the answers it gave me to choose @welshfella

Answer 7

yes it does make sense

the reqiured numbers are -4 and -9 because they multiply to + 36 and add to -13
so the factors are (x - 9)(x - 4)
look thru the list and the one you want is (x - 9)

Answer 8

follow?

Answer 9

you put all the effort in to explain and they just disappear!!