Answer:
(t - 4)(t + 2) = 0
Step-by-step explanation:
The general formula for a quadratic expression is
y = ax² + bx + c
Your expression is
y = t² - 2t - 8 = 0
By comparison, we see that
a = 1; b = -2; c = -8
1. Find two numbers that multiply to give ac and add to give b.
In this case, find two numbers that multiply to give -8 and add to give -2.
It helps to list the factors of -8.
They are ±1, ±2, ±4, and ±8
After a little trial and error, you should find the numbers -4 and +2.
-4 × 2 = -8, and -4 + 2 = -2)
2. Rewrite the middle term with those numbers
t² -4t + 2t - 8 = 0
3. Factor the first and last pairs of terms separately
t(t - 4) +2(t - 4) = 0
4. Separate the common factor
The common factor is t - 4.
(t - 4)(t + 2) = 0
