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>
2y + x = 4
x = -2y + 4
y = x^2 - 6x + 8
y = (-2y + 4)^2 - 6(-2y + 4) + 8
y = (-2y + 4)(-2y + 4) + 12y - 24 + 8
y = 4y^2 - 8y - 8y + 16 + 12y - 24 + 8
y = 4y^2 - 4y
4y^2 - 4y - y = 0
4y^2 - 5y = 0
y(4y - 5) = 0
y = 0 x = -2y + 4
x = -2(0) + 4
x = 4
4y - 5 = 0 x = -2y + 4
4y = 5 x = -2(5/4) + 4
y = 5/4 x = -10/4 + 4
x = -10/4 + 16/4
x = 6/4 which reduces to 3/2
so u have 2 sets of points that will work....
(4,0) and (3/2,5/4) <===
Answer:
The solution is (x,y)=(-4,-1)
Step-by-step explanation: Add the equations in order to solve for the first variable. Plug this value into the other equations in order to solve for the remaining variables.
Answer:
(x, y - 6)
Step-by-step explanation:
