Evaluating Rational Algebraic Expressions 200827042221 (1)

1. Evaluating Rational Algebraic
Expressions
Lorie Jane L. Letada
Module 3: Lesson 3
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November 26, 2020, Thursday, 2:00-3:00 PM
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2. At the end of this lesson, you are expected to:
 identify rational algebraic expressions
 determine the steps in evaluating a rational
algebraic expression; and
 evaluate a rational algebraic expression.
Objectives

3. Review Do you belong with me?
https://wordwall.net/resource/7142866/do-you-belong-me

4. https://www.google.com/search?q=a+teacher+printing+modules&tbm=isch&ved=2ahUKEwizjaqFvo3tAhUF0pQKHTmnC8
0Q2-
cCegQIABAA&oq=a+teacher+printing+modules&gs_lcp=CgNpbWcQAzoECCMQJ1DCywJYpNQCYIjWAmgAcAB4AIABpQKIAb
EOkgEDMi03mAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient=img&ei=I861X_PvE4Wk0wS5zq7oDA&safe=active#imgrc=EJD
0dYnqCJRkmM
Teacher Justin is
printing his module for
the students living in
the area which is
affected by the Enhanced
Community Quarantine due
to the Corona Virus. His
module has “x” pages. If
he printed 300 pages of
the module, how many
pages does each module
has if he has 10
students?

5. Questions:
1. Given the expression 10x = 300, how many pages does
each module has?
2. What if Teacher Justin printed 450 pages, how many
students can have the module given the value of x? (Let
y represents the number of students.
Show Solution
Show Solution

6. Solve it!
1. Given the expression 10x = 300, how many pages does
each module has?
𝟏𝟎𝒙
𝟏𝟎
=
Let x be the number of pages in each module has
𝟏𝟎𝒙 = 𝟑𝟎𝟎
𝟑𝟎𝟎
𝟏𝟎
𝒙 = 3𝟎 BACK

7. Solve it!
2. What if Teacher Justin printed 450 pages, how many
students can have the module given the value of x? (Let
y represents the number of students.
𝟑𝟎𝒚
𝟑𝟎
=
Let y be the number of students
30y = 𝟒𝟓𝟎
𝟒𝟓𝟎
𝟑𝟎
𝒙 = 𝟏𝟓

8. What is it
The expressions which are not polynomials are called rational algebraic
when a variable is substituted with a number in a rational expression, it is called
evaluating rational algebraic expressions.
Algebraic expressions can be evaluated by
substituting the given value in each quantity or
variable and performing the indicated operation. With
grouping symbols, operations within the grouping
symbol must be performed first before the other
operations.

9. Example 1. Evaluate the following rational expression.
330
10𝑥
; 𝑤ℎ𝑒𝑟𝑒 x = 3
330
10 (2)
Substitute the value of x.
330
30
Perform indicated operation.
11 Answer

10. Example 2. Evaluate the following rational expression.
5𝑘
3𝑘2+4𝑚
; 𝑤ℎ𝑒𝑟𝑒 k = 2 and m = -1
5(2)
3(2)2+4(−1)
=
Substitute
the value
of k and
m.
10
3 4 + 4(−1)
=
Perform
operations
in the
grouping
symbols.
10
12 − 4
=
10
8
Reduce to
lowest
term.
÷
2
2
=
What is
common factor
of numerator
&
denominator?
5
4

11. Sino ako?
Bugtong.. Bugtong..
Tagapamayapa ng sambayanan
May silbato at baril na tangan
Ito’y aking trabaho noon
At isang mambabatas na ngayon
Sino ako?

12. Evaluate each algebraic expressions when x = 1 and y = -3. Find the letter of
your answer and put it inside the box to form one word .
𝟏.
𝒙 𝟐
𝟑
𝟐.
𝒙 + 𝒚
𝟐
3.
𝒚+𝟐
𝒙+𝟏 4.
𝟐𝒀2
𝒙+𝟏
B =
1
3
⋅ A = -1
T = -
1
𝟐
O = 9
M =
1
𝟓
R = 1

13. 𝟏.
𝒙 𝟐
𝟑
; where x = 1 and y = -3
𝒙 𝟐
𝟑
=
𝟏 𝟐
𝟑
=
𝟏
𝟑
2.
𝒙+𝒚
𝟐
; where x = 1 and y = -3
𝟏 + (−𝟑)
𝟐
=
−𝟐
𝟐
= −𝟏
3.
𝒚+𝟐
𝒙+𝟏
= −𝟑+𝟐
𝟏+𝟏
=
−𝟏
𝟐
4.
𝟐𝒚2
𝒙+𝟏
=
𝟐(−𝟑)2
𝟏 + 𝟏
= 𝟐(𝟗)
𝟐
=
𝟏𝟖
𝟐
= 𝟐
Solution:

14. Sino ako?
Bugtong.. Bugtong..
Tagapamayapa ng sambayanan
May silbato at baril na tangan
Ito’y aking trabaho noon
At isang mambabatas na ngayon
Sino ako?
B OA T
Ronald M. dela Rosa, also known as
Bato, is a Filipino politician and
retired Police General who is
currently serving as Senator of the
Philippines since 2019.

15. Activity 1. Compute !

16. Answer Key

17. Answer Key

18. Answer Key

19. What I need to remember
 In evaluating a rational algebraic expression,
make sure that the denominator will not be equal
to zero as it will lead to “undefined”. Recall
the definition of rational algebraic
expressions.

20. Assignment
Please proceed to this link.
https://forms.gle/SwAkRFrAUB576PK26

21. “To accomplish great things ,
we must not only act but also
dream. Not only plan, but
also believe.” – Anatole
France