Answer:
x² – x – 12 = (x – 4)(x + 3)
Step-by-step explanation:
Identify two numbers that add to -1 and multiply to -12, let's call them p and q.
So ax² + bx + c = (x + p)(x + q)
pq = c
p + q = b.
It is easier to find these numbers by finding factors of -12.
This can be done by splitting the number up until all the numbers are prime.
-12 → 6 × -2 or -6 × 2 → -(3 × 2 × 2)
There can only be two numbers so the only options we have are 6 and -2, -6 and 2, 3, and -4, or -3 and 4.
We can eliminate them by adding them up.
6 + -2 = 4 ≠ -1 so that can't be it.
-6 + 2 = -4 ≠ -1 so that can't be it either.
-3 + 4 = 1 ≠ -1
therefore p and q are 3 and -4 because 3 + -4 = -1.
so x² – x – 12 = (x – 4)(x + 3)
p = -4, and q = 3.
(x – 4)(x + 3) = x(x + 3) – 4(x + 3) = x² + 3x – 4x + 12 = x² – x – 12
Answer:
there are nine dogs
Step-by-step explanation:
9 + 9 = ? We find out by addition, if there are 18 cats nine more cats than dogs; it is quite simple 9 and 9 is 18, so the number of dogs should be equal to the number of cats. hope this helps : )
Answer:
1/4
Step-by-step explanation:
This is correct on khan academy!
Answer: 1.25 hours
Step-by-step explanation: 600/120=5. Kin‘s travel time is 5 hours. 600/160=3.75. 5-3.75=1.25.
Answer:
I also don't know the answer to this question
