Answer:
x = 6
Step-by-step explanation:
Given that PQ = 3x + 14, QR = 7x - 10, and Q is the midpoint of PR, it means Q is equidistant from both endpoints of P and Q. In order words, the distance from P to Q is the same as the distance from Q to R.
Therefore, PQ = QR. Which is:
Solve for x. Collect like terms
Divide both sides by -4x
ivied distance by time:
100 meters / 15 seconds = 6.67 meters per second
Answer:
(a) x + 3(x + 4) = 5(x + 2) - 5
(b) youngest: 7 years old
middle: 9 years old
oldest: 11 years old
Step-by-step explanation:
(a)
We know that x is the youngest child's age. Since the sisters' ages are consecutive odd integers, we know that the ages differ by 2. So, the middle sister's age is x + 2 and the oldest sister's age is x + 4.
Our equation to model the sentence "the sum of the age of the youngest and three times the age of the oldest is five less than five times the middle sister's age" would be:
x + 3 * (x + 4) = 5 * (x + 2) - 5
x + 3(x + 4) = 5(x + 2) - 5
(b)
Now, we can just solve the equation above:
x + 3(x + 4) = 5(x + 2) - 5
x + 3x + 12 = 5x + 10 - 5
4x + 12 = 5x + 5
x = 12 - 5 = 7
So, the youngest sister is 7 years old.
That means the middle sister is 7 + 2 = 9 years old, and the oldest sister is 9 + 2 = 11 years old.
The ages, then, are:
youngest: 7 years old
middle: 9 years old
oldest: 11 years old
The nature of the roots can be determined by the determinant of the equation. The determinant is:
b² - 4ac
If this is positive, there are two roots
If this is 0, there is only one root
If this is negative, there are complex roots
A.) -5/8 = -5/8 or 5/-8
b.) -7/-10 = 7/10