LESSON 7
ALGEBRA: Use of Letters in Mathematics
MATHEMATICAL OPERATIONS WITH
ALGEBRAIC TERMS
Mathematical operations are the
basic operations carried out in mathematics. Examples are multiplication (x),
division (÷), addition (+), subtraction (-) e.t.c.
We are going to discuss the addition
and subtraction of algebraic terms in this lesson. Let’s go!
ADDITION
AND SUBTRACTION OF ALGEBRAIC TERMS
Let’s start with addition of simple
algebraic terms
EXAMPLE 1
Simplify a + a + a
SOLUTION
a + a + a = 3a
NOTE
1.
2 + 2 + 2 = 3 x 2 (3 times of 2)
compare to a + a + a =3 x a (3 times of a)
2.
In algebra, the number that
multiplies a letter is called coefficient while the letter is called the
variable. Therefore
(i) In 3a,
3 is the coefficient and a is the variable
(ii) In ¾ a, ¾ is the coefficient and a is the variable
(iii) In -2x, -2 is the
coefficient and x is the variable
(iv) In p, 1 is the coefficient and p is the variable.
Did
you understand this? Go over it again and be sure!
EXAMPLE 2
Simplify 3x + 2x
SOLUTION
3x + 2x = (x + x + x) + (x
+ x) That
is (3 times of x) + (2 times of x)
= x + x + x + x + x
= 5x (5 times of x)
OR
3x + 2x = (3 +2)x
= 5x
EXAMPLE 3
Simplify 4p + 6p
SOLUTION
4p + 6p = (p + p + p + p)
+ (p + p + p + p + p + p)
= p + p + p + p + p + p + p + p +
p + p
= 10p
OR
4p + 6p = (4 + 6)p
= 10p
LET’S PUSH IT IN!
Give quick answers to the following
questions and write them in your pad.
(i) What is the
coefficient of -10p?
(ii) What is the simplified form of x + x?
(iii) What is the simplified form 5q + 3q?
Check if your answers are the same
as
(i) -10 (ii) 2x (iii) 8q
If they all the same as your answer,
go to the ACTIVITY, if not back to the examples again!
ACTIVITY
Simplify the following
1. p + 2p
2. 4b + 4b
3. x + 9x
4. 5g + 9g
5. 5y + 13y + 2y
Post the solution as a COMMENT to
this lesson. Include your name or nickname and email because every COMMENTS
will be replied. I’m expecting your COMMENT.
Congratulation! You've completed
this lesson. Now let's go to LESSON 8: MATHEMATICAL OPERATIONS WITH ALGEBRAIC
TERMS – SUBTRACTION.