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:
314 square feet
Step-by-step explanation:
we know that
The area that will be covered by the spray of the quarter-circle sprinkler head, is equal to the area of a quarter circle with radius of 20 feet
so
The area of a quarter circle is

we have


substitute

Step-by-step explanation:
x+9-10=500
x-1=500
x=500+1=501
Answer:
$56 or $4 left over from $60
$ 56 o $ 4 sobrantes de $ 60
Step-by-step explanation:
4 2/3 pizzas would cost $56
4 2/3 pizzas costarían $ 56