Answer:
Below.
Step-by-step explanation:
a. Φ^2 − Φ − 1 = 0
Φ2 − Φ = 1
(Φ - 0.5)^2 - 0.25 = 1
(Φ - 0.5)^2 = 1.25
Φ - 0.5 = √(1.25) (We only take the positive root).
Φ = 0.5 + √(1.25)
b. I used Completing the square.
c. Φ is irrational That is it cannot be represented as a fraction a/b and because of this it can only be approximated by a decimal.
Answer:
The number is -3.
Step-by-step explanation:
Set up an equation:
Variable n = number
12 + 7n = n - 6
Assuming the question is solve for n, isolate the variable:
Subtract n from both sides:
12 + 6n = -6
Subtract 12 from both sides:
6n = -18
Divide by 6 on both sides:
n = -3
Check your work:
12 + 7(-3) = -3 - 6
12 - 21 = -3 - 6
-9 = -9
Correct
Answer:
x = 7.5
Step-by-step explanation:
Given that BE is parallel to CD and intersects the 2 other sides, then it divides the 2 sides in proportion, that is
= 
, substitute values
= 
( cross- multiply )
8x = 60 ( divide both sides by 8 )
x = 7.5
The answer would be $697.5
Hope this helps!
