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 population of 75 hours from now would be 40,000.
Step-by-step explanation:
The reason for this is because your initial number is 10,000 and when 25 hours pass by, your population would be 20,000. Another 25 hours pass by, and then your population would be 40,000. If you multiply 25 by 3, you will notice 75 hours have just passed, so your answer would be 40,000.
Answer:
❥
Diameter of a circle is 8 cm. Then find out the area and perimeter of the circle.
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Area of circle is 50.29(≈)cm² and perimeter of circle is 25.14(≈)cm.
❥
•Given :-
Diameter of the circle = 8 cm.
•To find :-
Area and perimeter of the circle.
• Solution :-
Let the radius of the circle be r cm.
Diameter = 8 cm.
We know,
★
So, Radius (r) = 8/2= 4 cm.
We know,
★
Area of circle= πr²
→Area of circle=
→Area of circle=
→Area of circle= 50.29(≈)cm²
____________________________
We know,
★
Perimeter of circle= 2πr
→ Perimeter of circle=
→Perimeter of circle=25.14(≈)cm
Answer:the company bought 12 computers and 4 printers.
Step-by-step explanation:
Let x represent the number of computers that the company bought.
Let y represent the number of printers that the company bought.
The company buys a total of 16 machines. It means that
x + y = 16
Each computer costs $550 and each printer costs $390. If the company spends $8160 for all the computers and printers that was bought, it means that
550x + 390y = 8160 - - - - - - - - - - 1
Substituting x = 16 - y into equation 1, it becomes
550(16 - y) + 390y = 8160
8800 - 550y + 390y = 8160
- 550y + 390y = 8160 - 8800
- 160y = - 640
y = - 640/ - 160
y = 4
Substituting y = 4 into x = 16 - y, it becomes
x = 16 - 4
x = 12
triangle area: 19cm×17.5cm÷2=166.25
square area: 19cm×19cm=361
all:361+166.25×4=1026
