Page 36 - WCS - Electrical

WORKSHOP CALCULATION & SCIENCE - CITS

The innermost set in a grouping symbols of an expression is to be simplified first.
Algebraic symbols and simple equations
Algebraic symbol
An unknown numerical value of a quantity is represented by a letter which is the algebraic symbol.

Factor
A factor is any one of the numbers or letters or groups which when multiplied together give the expression.
Factors of 12 are 4 and 3 or 6 and 2 or 12 and 1.
8x + 12 is the expression and this may be written as
4(2x + 3), 4 and (2x + 3) are the factors.

Algebraic terms
If an expression contains two or more parts separated by either + or –, each part is known as the term.
y – 5x is the expression. y and – 5x are the terms.
The sign must precede the term.
Kinds of terms:

1 Like terms
a 13a, 15a, 19a, -12a, -18a
b 5xy, 11xy, -xy, -14xy
c 27m , 25m , -3m , 11m 2
2
2
2
2 Unlike terms
a 3ac, - 4b, 8x, 3yz
b 2xy, y , a b, xz, 3bc
2
2
c 13m n, 3mn , 14lm , 15a b, 5lm
2
2
2
2
Examples :
1 Add 7a, - 2a, a, 3a
7a + (- 2a) + (a) + 3a
7a - 2a + a + 3a
= 11a - 2a
= 9a
2 Add 25xy, + 2xy, - 6xy, - 3xy

25xy + 2xy + (- 6xy) + (- 3xy)
= 27xy - 9xy
= 18xy
3 Add 9m, + 4m, - 2

9m + 4m + (- 2)
9m + 4m - 2
= 13m - 2
Coefficient
When an expression is formed into factors whose product is the expression, then each factor is the coefficient of
the remaining factors.

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CITS : WCS - Electrical - Exercise 4