Maths Form 2 = Chapter 1,2 & 3

Maths Form 2 CHAPTER 1, 2 and 3 

( BY : ASHVINI SEKAR )

CHAPTER 1 : DIRECTED NUMBERS

              1.1 Multiplication and Division of Integers


        RULES for multiplication of integers : (A) + x + = +
                                                                     (B) + x - = -
                                                                     (C) - x + = -
                                                                     (D) - x - = +
                                                                     (E) + x 0 = 0
                                                                     (F) - x 0 = 0
     
        RULES for division of integers : (A) + divided by + = +

                                                             (B) + divided by - = -
                                                              (C) - divided by + = -
                                                              (D)  - divided by - = +
                                                             (E)  0 divided by + = 0
                                                              (F) 0 divided by - = 0


  1.2 Positive and Negative fractions

        1. Fractions can be marked on a number line.
        2. A positive fraction is a fraction with or without a positive sign, (+) and has a value greater than          
            zero.
        3. A negative fraction is a fraction with a negative sign (-), and has a value greater than zero.

      4. On a horizontal number line, positive fractions are those to the right of 0 while negative   fractions are those to the left of 0.

        

    

  5. On a vertical number line, positive fractions are those above zero, whereas negative fractions

          are those below 0.

     Positive & negative decimals 

1. Decimals can be marked on a number line 

2. A positive decimal number is to the right of zero whereas a negative decimal number is to the left of zero.

Computations involving Directed Numbers (integers, fractions, and decimals) 

1. When performing computations involving a combination of +, - x, divide and ( ), follow these rules :          

BODMAS : B = Do equations in brackets first.
o = of
D & M = Perform multiplication & division from left to right.
A & S = Lastly, do addition & subtraction from left to right.

Notes Mathematics Form 2 - Chapter 2: Squares, Square Roots, Cubes and Cube Roots.

Squares of numbers can be either positive or negative. Usually we write positive squares without bracket and negative squares with bracket.

Square root only available for positive numbers. You can prove this by using calculator. You are going to get MATH ERROR for square root of negative numbers.

Cubes and cube roots have the same rule. It both can be either positive or negative numbers, depends on the questions. Positive cubes or cube roots give positive answers while negative cubes or cuber roots give negative answers.

  CHAPTER 3 : ALGEBRAIC EXPRESSIONS (III)

 QUESTION 1
Simplify cd + ef – gh – 2(4gh + 7ef – 5cd).

QUESTION 2
Simplify 3(4cd – 3jl) – (5jl – cd)

QUESTION 3
Simplify (12ng – 3nl) – (10gn – 3ln)

QUESTION 4
Evaluate the expression below. Given j = 3, k = -1 and l = 4.

QUESTION 5
If p = 2 and q = 3, evaluate the expression below.