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JSS2: MATHEMATICS - 2ND TERM

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  1. Transactions in the Homes and Offices | Week 1
    8 Topics
    |
    1 Quiz
  2. Expansion and Factorization of Algebraic Expressions | Week 2
    4 Topics
    |
    1 Quiz
  3. Algebraic Expansion and Factorization of Algebraic Expression | Week 3
    4 Topics
    |
    1 Quiz
  4. Algebraic Fractions I | Week 4
    4 Topics
    |
    1 Quiz
  5. Addition and Subtraction of Algebraic Fractions | Week 5
    2 Topics
    |
    1 Quiz
  6. Solving Simple Equations | Week 6
    4 Topics
    |
    1 Quiz
  7. Linear Inequalities I | Week 7
    4 Topics
    |
    1 Quiz
  8. Linear Inequalities II | Week 8
    2 Topics
    |
    1 Quiz
  9. Quadrilaterals | Week 9
    2 Topics
    |
    1 Quiz
  10. Angles in a Polygon | Week 10
    4 Topics
    |
    1 Quiz
  11. The Cartesian Plane Co-ordinate System I | Week 11
    3 Topics
    |
    1 Quiz
  12. The Cartesian Plane Co-ordinate System II | Week 12
    1 Topic
    |
    1 Quiz
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Topic Content:

  • Word Problems Leading to Inequalities

The key to word problems is translating the given information into math language. In this case, we need to translate word problems into statements of inequality.

Example 8.2.1:

If x is subtracted from 5 and the result is greater than 15. Find the range of values of x.

Solution 

x subtracted from 5

5 – x

Result > 15

\( \scriptsize 5 \: – \: x > 15 \)

Collect like terms

\( \scriptsize 5 \: – \: x > 15 \)

\( \scriptsize -x > 15 \: – \: 5 \)

\( \scriptsize -x > 10 \)

Divide both sides by -1 (reverse the sign) 

\( \frac {-x}{-1} < \frac{10}{-1} \)

\( \scriptsize x < -10 \)

Range of values of x :  -11, -12, -13, … 

Example 8.2.2: 

Olu is x years old. In 4 years time his age will still be less than 12 years. 

(a) Write this information in an inequality in x
(b) Find the maximum age of Olu to the nearest whole number 

Solution 

(a) In 4 years time, Olu will be (x + 4) years 

x + 4 is less than 12 

\( \scriptsize x \: + \: 4 < 12 \)

(b) Solve \( \scriptsize x \: + \: 4 < 12 \)

collect like terms

\( \scriptsize x < 12 \: – \: 4 \)

\( \scriptsize x < 8\)

Range of values of x:  7, 6, 5, 4, 3, …

The maximum age of Olu is 7 years.