Answer:
(x + 9)(x - 8)
Step-by-step explanation:
f(x) = x^2 + x - 72
= x^2 - 8x + 9x - 72
= (x^2 - 8x) + (9x - 72)
= x(x - 8) + 9(x - 8)
= (x + 9)(x - 8)
Let the slower runners speed be X kilometers per hour.
Then the faster runners speed would be X+2 kilometers per hour.
The formula for distance is Speed times time.
The distance is given as 30 kilometers and time is given as 3 hours.
Since there are two runners you need to add the both of them together.
The equation becomes 30 = 3x + 3(x+2)
Now solve for x:
30 = 3x + 3(x+2)
Simplify:
30 = 3x + 3x +6
30 = 6x + 6
Subtract 6 from each side:
24 = 6x
Divide both sides by 6:
x = 24/6
x = 4
The slower runner ran at 4 kilometers per hour.
The faster runner ran at 4+2 = 6 kilometers per hour.
Answer:
D
Step-by-step explanation:
The answer is 6
1) should be second option
CD→
2) None of these
