How do you do this ?
1 answer:
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Answer:
The book costs $2 and the pencil also costs $2.
Step-by-step explanation:
It is easy to get the value of the book and the pencil if we use<em> algebraic expressions.</em>
Let x be the cost of the book and let y be the cost of the pencil.
The sum of 2 books and a pencil is $6.00
- 2x + y = $6.00
The difference of cost between 3 books and 2 pencils is $2.00.
- 3x - 2y = $2.00
Step 1: Let's get the value of y first.
2x + y = 6
y = 6 - 2x
Step 2: Let's substitute the value of y and look for the value of x.
3x - 2y = $2.00
3x - 2(6-2x) = 2
3x - 12 + 4x = 2
7x = 12 + 2
7x = 14
x =
x = $2 (this is the cost of the book)
Step 3: Let's substitute the value of x and look for the value of y.
2x + y = 6
2 (2) + y = 6
4 + y = 6
y = 6 - 4
y = $2 (this is the cost of the pencil)
Let's check:
2x + y = $6
2(2) + 2 = 6
4 + 2 = 6
6 = 6<em> (CORRECT)</em>
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Answer:
See below
Step-by-step explanation:
π, pronounced as <em>pi</em> is the ratio between 2πr which is circumference to 2r which is diameter.
In word, π is circumference/diameter which has exact value of 3.14159... and it is also an irrational number too.
π is often used to be defined as 3, 3.14 or 22/7 [Keep in mind, these numbers are only approximation.] in some fields. In trigonometry, π is mostly used to refer as <u>π radians</u> or <u>π rad</u> which is equivalent to 180°.
Why do we need it? Because it’s useful in a field that requires rotation. If you notice, figure with circular base will always have π with it, the volume is an example.
In calculus, you need π to do solid of revolution method which is:
In trigonometry, you need it for measurement/angle.
So anything that’s related to revolution, rotation or related to circle must require π at least.
In general life, you do not use it but this is mostly applied in engineering field and anything related to science that involves with circle or revolve.
Let me know if you have any questions!