The formula of an area of a rectangle:
A = wl
We have l = w - 4 and A = 21.
Substitute:
w(w - 4) = 21 <em>use distributive property</em>
(w)(w) + (w)(-4) = 21
w² - 4w = 21 <em>subtract 21 from both sides</em>
w² - 4w - 21 = 0
w² - 7w + 3w - 21 = 0
w(w - 7) + 3(w - 7) = 0
(w - 7)(w + 3) = 0 ↔ w - 7 = 0 ∨ w + 3 = 0
w = 7 ∨ w = -3 < 0
l = w - 4 → l = 7 - 4 = 3
<h3>Answer: the length = 3 u.</h3>
Answer: D The square root of 100 is 10. Or,
√100 = 10
Step-by-step explanation:
Answer:
The North and South poles on the bar magnets attract to one another when they are placed near each other. When the North and North or the south and south are placed near each other, they repel away from each other.
I hope this helps :)
C. it's obvious that humans will never travel to planets near even thwe closest stars.
