Week 9 – Jss 2 First Term Mathematics Lesson Notes

WEEK 9        ALGEBRAIC EXPRESSION

 To expand algebraic expression, those expression will have to be in bracket. When the bracket ever moved, then any factor outside the bracket must be multiplied by each term inside bracket.        
Example 1: Expand d(a + c)
Solution: d * a + d * c = da + dc
Example 2: Expand (y + 3)( y + 4)
Solution:
= Y * Y + Y * 4 + 3 * Y + 3 * 4
= Y² + 4y + 3y + 12
FACTORIZATION OF SIMPLE ALGEBRAIC EXPRESSION
Factorization is the reverse of expanding brackets. The first step in factorization is to take any commom factor which the term are:
Example 1 :Factorise 3^X2 + X
Solution:
X is common to the expression
Therefore = X(3X + 1)
Example 2: Factorize 6y³ – 4y² – 4y
Solution:
2y is common in the expression
Therefore 2y(3y² -2y -2

 ALGERAIC EXPRESSION WITH FRACTIONS
Example 1: Solve X/3 + X- 2/5 = 6
Solution:
Find the L C M = 15
5x + 3X – 6 /15 = 6
Cross multiply
= 5X + 3X – 6 = 6*15
8X – 6 = 90
Add 6 to both sides = 8X – 6 + 6 = 90 + 6
8X = 96 (Divide both sides by 8)
X = 12.
FINDING LOWEST COMMON FACTOR AND HIGHEST COMMON FACTOR IN ALGEBRAIC FORM
Example 1: Find the L C M of 4xy,8xv and 10x²y
Solution:
2 4xy 8xy 10x²y
2 2xy 4xy 5x²y
2 xy 2xy 5x²y
5 xy xy x²y
X xy x y x²y
X y y xy
Y y y y
1 1 1
L C M = 2 * 2 * 2 * 2 * 5 * X * X * Y = 40X²Y
Example 2: find the H C F of 4xy, 8xy and 10x²y
Solution;
4xy = 2 * 2 * x * y
8xy = 2 * 2 * 2 * x * y
10x²y = 2 * 5 * x * x * y
H C F = 2 * X * Y = 2XY

 ASSESEMENT: ESSENTIAL BOOK FOR JSS 2
EXERCISE 11.4 NO 25 – 35. PAGE 138.
EXERCISE 11.8 NO 2 (F, G & H), NO 4(E&F), NO 11(A, B, C & D). PAGE 143