### (8 March 2011) Chapter 4: Vocabulary in Algebra

(I) Algebraic Expressions vs Equations
The following are expressions
• 3x
• 5 - 2y
• p + 2q - 45
• mn
The following are equations:
• 2x = 4
• x + 8 = 20
• x² = 36
• 2x + y = 4
Can you tell the difference between an expression and an equation?

(II) Coefficients, Variables and Constants
In the following algebraic expressions:

(a) 6x
• x is a variable
• 6 is the coefficient of x
• There is no constant
(b) 2y + 5
• y is a variable
• 2 is the coefficient of y
• 5 is the constant
(c) 3m + 7n + 9
• m and n are variables
• 3 and 7 are coefficients of m and n respectively
• 9 is the constant
(d) p + 2q - 45
• p and q are variables
• 1 and 2 are coefficients of p and q respectively
• -45 is the constant
(e) 5a - 3b + 1
• a and b are variables
• 5 and -3 are coefficients of a and b respectively
• 1 is the constant
(f) x - y
• x and y are variables
• 1 and -1 are coefficients of x and y respectively
• There is no constant
When given an expression, are you able to pick out the variable(s), coefficient(s) and constant terms?

Let's learn more terms that are related to Algebra through the Hangman activity (select "Algebra")

1. Coefficient means the number in an algebraic expression.
E.g. In 9x, 9 is the coefficient
In !0x + 3y, 3 and 10 are coefficients.

2. Coefficient is the numerical value in an algebraic expression.
Example : In 10n , 10 is the coefficient

3. Coefficients are numbers placed at the front of an unknown to show that the unknown is multiplied by that number.
examples: In 4y, the coefficient of y is 4.
In y, the coefficient of y is 1 but we do not put 1y because 1*y=y
Coefficients can also be negative numbers example: In -2y, -2 is the coefficient of y.

4. Coefficient is the amount of times the unknown number is multiplied by in an algebraic expression. For example: 35x = 35 multiplied by x (unknown number)

5. Coefficient is the numerical part of the algebraic expression. It is placed to show that the numerical part is multiplied by the unknown(letter).
For example: 2y : 2 is the coefficient.

6. Coefficient(2) is a real number before a variable(e.g. x). For example, in 2x, the 2(numeral;coefficient) would be the coefficient while the 'x' is the variable. BTWFYI I'm Ishani

7. Coefficient is the numerical part which is later on multiplied by the variable.
An example is 3y. 3 is the coefficient in this case.

8. Coefficient is the numerical value in an algebraic expression.
For example, 2a=>2 is the coefficient.
2a+11b=> 2 and 11 are the coefficients.

9. Thank you to the above responses :)

I think Wei Siew has given a very clear explanation on what's an coefficient, with several useful examples.

As some of you pointed out correctly, it refers to the value placed in front of a variable.

10. Coefficients are numbers placed at the front of a variable to show that the variable is multiplied by that number.
Eg: In 8a, 8 is the coefficient of a or in 9z, 9 is the coefficient of z.
Coefficients can also be negative numbers example: In -6h, -6 is the coefficient of h.