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:

Step-by-step explanation:
A polynomial written in decreasing order of the degree of its monomials ( or single term ) is called its standard form,
In polynomial,
,
Degrees are written in increasing order,
⇒ It is not written in standard form,
In polynomial,
,
Degrees are written in decreasing order,
⇒ It is written in standard form,
In polynomial,
,
There is no order of degrees,
⇒ It is not written in standard form,
In polynomial,
,
There is no order of degrees,
⇒ It is not written in standard form,
which of the following numbers, -2/3, 0, 1/2, pie, 11/15, 25, 12, -5, 0.75, -1.82828282828282828282 are rational, irrational, wh
dexar [7]
Answer:
Step-by-step explanation
i need points soryyyyyyyyyyyyyyyy
Answer:
Solution given:
x^3 - 2x^2 -x+2
take common from two each term
x²(x-2)-1(x-2)
take common again and keep left one on other bracket
<u>(x-2)(x²-1) or (x-1)(x+1)(x-2)</u> is a required answer.
note:using formula a²-b²=(a+b)(a-b) for x²-1.