CHAPTER 2

Question 0

Addition and subtraction of like terms

Answer 0

Only like terms can be subtracted or added:
Eg) 7ab + 2ab +2c
=9ab + 2c

Question 1

Substitution of x = 3, 2x + 4

Answer 1

2 x 3 +4

=10

Question 2

Inequalities on a line?

Answer 2

> = open circle pointing right
< = open circle pointing left
_> = closed circle pointing right
<_ = closed circle pointing left

Question 3

Solving inequalities?

Answer 3

Eg) 4-2x < 6

= x> -3 (reverse sign if negative number)

Question 4

Simple quadratic expressions?

Answer 4

X^2 = 9
x= +-|9

Question 5

Simultaneous equations?

Answer 5

2x + y = 12.     (1)
        y = x + 3 (2)
2x + (x+3) = 12
3x +3 = 12 
x=3 

(2) y= 3+3
= 6

Question 6

Elimination?

Answer 6

eg) x + 2y = 2    (1)
      2x + 3y = 5   (2)
      2x + 4y = 4   (3)
 y= -1
x+ 2(-1) = 2
x-2= 2
x=4