Evaluating Algebraic Expressions

3. MECHANICS:
• Suppose numbers are assigned to
letters of the alphabet as follows
A=1, B=2, C=3, D=4, E=5, and so on, up to
Z=26
using this, you will find the value of
a word/name by(any operations) to
get the values of its digits.

4. MARY
= M + A + R + Y
= 13 + 1 + 18 + 25 = 57

5. • In this game we have 2
rounds to play, EASY
round compose of 1 word,
and AVERAGE compose of
2 words.

7. A=1, B=2, C=3, D=4, E=5, F=6, G=7, H=8,
I=9, J=10, K=11, L=12, M=13, N=14, O=15,
P=16, Q=17, R=18, S=19, T=20, U=21, V=22,
W=23, X=24, Y=25, Z=26

8. E+Q+U+A+L+I+T+Y
= 5+17+21+1+12+9+20+25
= 110

10. A=1, B=2, C=3, D=4, E=5, F=6, G=7, H=8,
I=9, J=10, K=11, L=12, M=13, N=14, O=15,
P=16, Q=17, R=18, S=19, T=20, U=21, V=22,
W=23, X=24, Y=25, Z=26

11. (S-U-M)2
= (19)-(21)-(13)
= (-15)2
= 225

12. A=1, B=2, C=3, D=4, E=5, F=6, G=7, H=8,I=9,
J=10, K=11, L=12, M=13, N=14, O=15, P=16,
Q=17, R=18, S=19, T=20, U=21, V=22, W=23,
X=24, Y=25, Z=26

13. V-A-R-I-A-B-L-E
= (22)-(1)-(18)-(9)-(1)-(2)-(12)
-(5)
= -26

15. Algebraic Expressions
a statement containing one or
more terms connected by plus
or minus signs.

16. Examples:
1. 4x + 3
2. 5x2 – 3x + 4

17. Two steps involved in
evaluating an algebraic
expression:

18. 1. Replacing the variable by the given
number value (substitution);
4x + 3 X = 2
4(2) + 3

19. Substitution Property of Equality
If two quantities are equal,
then one quantity can be replaced
by the other.
In symbols:
For all numbers a and b, if
a=b, then a may be
replaced by b.”

20. 2. Performing the indicated
arithmetic following the
order of operations.

21. - First, simplify expressions within
grouping symbols.
- Then simplify powers
- Then simplify products and quotients in
order from left to right
- Then simplify sums and
differences in order form
left to right.

22. Example:
• 3x2 – 5 x = 4
3(4)2 - 5
3(16) - 5
48 - 5
43

23. Activity:
• Evaluate the polynomial 6x2 + 3
when:
a. x=0
b. x=3
c. x= -4
d. x= -1/2

24. QUIZ:
Find the value of the following Algebraic
Expressions using the indicated constants.
(2pts. Each)
1. 9a + 3; a=5
2. 15a – 24b +15; a=3, b=2
3. (x+3) (x-5); x=25
4. (50a) (2-9); a=4
5. 4a ÷ (13 – 9b); a=12 and
b=1/3

25. Assignments
Answer to your notebook.
1. Write the Steps in adding polynomials.
2. Answer this following to your notebook:
a. (-6 x -3) + (3 x -9)
b. (3x² + 5x -9) + (-3 x + 4)
c. (4x² + 3x +6) + (6x² + 3x -7)
d. (2ab² + 2a³b - 4ab) + (4a²b - 3ab - 2a²b)
e. (5x² + 10xy + 4y²) + (7x² + 8xy - 6y²)
Reference: Grade 7 E-math k-12 edition
pages 169-171