MAth 6 LEsson 3

1. MATHEMATICS 7

2. SIMPLIFYING and EVALUATING
ALGEBRAIC EXPRESSIONS
In this lesson, you will be able to …
⮚Explain the concepts of algebraic terms,
numerical coefficients and literal coefficients
⮚Simplify an expression by combining like terms
and by using the distributive property of
multiplication

3. Algebraic Expression
5n 10x + 5 5a – 6b + 8
1 term 2 terms 3 terms
An expression may contain like or similar terms.
7x and 2x -3xy and xy
Like terms
8x and 3y -5ab and 7c
Unlike terms
Like terms

4. It does not have like or similar terms. Such expression is in its simplest form.
▪ When expressions contain similar terms, we simplify them by combining like
terms. One way of doing this is by using the Distributive Property of
Multiplication, ac + bc = (a + b)c.
Example:
2x + 3x = (2 + 3)x = 5x
▪ It is also easy to simplify expressions by combining like terms mentally.

5. ▪ In evaluating an algebraic expression, we substitute the given value in each
variable and perform the indicated operations using MDAS. In cases where
exponents and grouping symbols are involved we apply GEMDAS.
Example:
Evaluate x + 21, for x = 5.
(5) + 21 = 26
Evaluate 2(6x – 3y), for x = 10 and y = 15.
= 2[6(10) – 3(15)]
= 2(60 – 45)
= 2(15)
= 30
= 2[6(10) – 3(15)]
= 2(60 – 45)
= 120 – 90
= 30

6. = 145
Evaluate 3[-x +(2y – 3z) + 10], for x = 3, y = 1, and z = 2.
= 3[-(3) +(2(1) – 3(2)) + 10]
= 3[-3 + (2 – 6) + 10]
= 3[-3 + (– 4) + 10]
= 3[-7 + 10]
= 3[3]
= 9

7. ▪ A TERM is a part of an algebraic
expression contained between the
operations of addition or
subtraction. It is a product of the
coefficient and the variable/s.
▪ To simplify algebraic expressions, combine
like terms.
▪ To evaluate an algebraic an algebraic
expression is to substitute the given value of
each variable in the expression and perform
the indicated operations.

8. and God bless!
☺