Answer: 15.7 minutes
Step-by-step explanation:
Let x be the time in the beginning (in minutes).
Given: The track team is trying to reduce their time for a relay race.
First they reduce their time by 
2.1 minutes.
Then they are able to reduce that time by 
10
If their final time is 3.96 minutes, then
Hence, their beginning time was 15.7 minutes.
Hence the circumference of the circle is: 6π or 18.84 units
So first you have to find the perfect square that matches up with x^2 + 6x
so half of 6, and square it. your perfect square is 9
x^2 + 6x + 9 = 7 + 9
then, condense the left side of the equation into a squared binomial:
(x + 3)^2 = 16
take the square root of both sides:
x + 3 = ± √16
therefore:
x + 3 = ± 4
x = - 3 ± 4
so your solution set is:
x = 1, -7
She will need 12 seconds because -20•12=-240
Answer:
D
Step-by-step explanation:
If two lines are perpendicular, the products of their slopes will be -1. Therefore, we're looking for a line with slope of -1/2. Let's check each answer:
A: 5 - 3 / (-2 - 3) = 2 / -5
B: 6 - 5 / 6 - 5 = 1
C: 5 - 3 / 4 - 3 = 2
D: 4 - 3 / 3 - 5 = -1/2
The answer is D.
