<h3>
Answer: True</h3>
Explanation:
This theorem doesn't have a name unfortunately. So searching it out is a bit tricky if you don't know the right way to word things. Luckily it wasn't too hard of a find, and I managed to track it down in a linear algebra textbook.
Check out the screenshot below for the snippet of the theorem and the corresponding proof. The book simply refers to it as "theorem 1.9", which again, is an unfortunate choice of naming.
![\bf \stackrel{\textit{perimeter of a rectangle}}{P=2(L+w)}~~ \begin{cases} L=length\\ w=width\\ \cline{1-1} P=66 \end{cases}\implies 66=2(L+w) \\\\\\ 33=L+w\implies \boxed{33-w=L} \\\\[-0.35em] ~\dotfill\\\\ \stackrel{\textit{area of a rectangle}}{A=Lw}\qquad \implies 216=Lw\implies 216=(33-w)w \\\\\\ 216=33w-w^2\implies w^2-33w+216=0 \\\\\\ (w-24)(w-9)=0\implies w= \begin{cases} 24\\ 9 \end{cases}](https://tex.z-dn.net/?f=%5Cbf%20%5Cstackrel%7B%5Ctextit%7Bperimeter%20of%20a%20rectangle%7D%7D%7BP%3D2%28L%2Bw%29%7D~~%20%5Cbegin%7Bcases%7D%20L%3Dlength%5C%5C%20w%3Dwidth%5C%5C%20%5Ccline%7B1-1%7D%20P%3D66%20%5Cend%7Bcases%7D%5Cimplies%2066%3D2%28L%2Bw%29%20%5C%5C%5C%5C%5C%5C%2033%3DL%2Bw%5Cimplies%20%5Cboxed%7B33-w%3DL%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20%5Cstackrel%7B%5Ctextit%7Barea%20of%20a%20rectangle%7D%7D%7BA%3DLw%7D%5Cqquad%20%5Cimplies%20216%3DLw%5Cimplies%20216%3D%2833-w%29w%20%5C%5C%5C%5C%5C%5C%20216%3D33w-w%5E2%5Cimplies%20w%5E2-33w%2B216%3D0%20%5C%5C%5C%5C%5C%5C%20%28w-24%29%28w-9%29%3D0%5Cimplies%20w%3D%20%5Cbegin%7Bcases%7D%2024%5C%5C%209%20%5Cend%7Bcases%7D)
now, both values are valid, so if "w" is either one, "L" is the other.
Answer:
a can be any real number less than equal to -5
Step-by-step explanation:
When a+5 is negative,
a + 5 = -(-5 - a)
a + 5 = a + 5
All values satisfy the equation
So a < -5
When a + 5 is greater than/equal to 0,
a + 5 = -a - 5
2a = -10
a = -5
a can be any real number less than equal to -5
Answer:
583 miles
Step-by-step explanation:
Let's draw this out (see attachment).
The straight line path creates the hypotenuse of a right triangle with legs of lengths 300 and 500. So, we use the Pythagorean Theorem, which states that for a right triangle with legs a and b and hypotenuse c:
a² + b² = c²
Here, a = 300 and b = 500. Then:
300² + 500² = c²
90000 + 250000 = c²
340000 = c²
c = √340000 ≈ 583.1 ≈ 583 mi
Thus, the answer is 583 miles.
<em>~ an aesthetics lover</em>
Answer:
3(x - 12)(x + 2)
Step-by-step explanation:
Given
3x² - 30x - 72 ← factor out 3 from each term
= 3(x² - 10x - 24) ← factor the quadratic
Consider the factors of the constant term (- 24) which sum to give the coefficient of the x- term (- 10)
The factors are - 12 and + 2 , since
- 12 × 2 = - 24 and - 12 + 2 = - 10 , thus
x² - 10x - 24 = (x - 12)(x + 2) and
3x² - 30x - 72 = 3(x - 12)(x + 2)