Using Algebra to Solve Problems

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Using Algebra to Solve Problems. Form 1 Mathematics Chapter 2 and Chapter 4. Revision. “ >”: Greater than “ ” and “=” “”: Less than or equal to (or Not greater than) A combination of “

Text of Using Algebra to Solve Problems

  • Form 1 MathematicsChapter 2 and Chapter 4

  • Ronald HUI>: Greater than

    and =

    : Less than or equal to (or Not greater than)A combination of

  • Ronald HUIP.166 Question 9: Add 5 to 4 times of a number p and the sum is greater than 33.

    Add 5 +54 times of a number p 4pThe sum 4p+5Then, the inequality is 4p+5 > 33

    Ronald HUI

  • Ronald HUIP.166 Question 11: When the sum of a number s and 3 is multiplied by 2, the product is smaller than -10.

    The sum of s and 3 s+3Multiplied by 2 2The product (s+3) 2 or 2(s+3)The inequality is 2(s+3) < -10

    Write 3 numbers by guessing!

    Ronald HUI

  • Ronald HUIP.166 Question 13a: Mike has 2 packs of $1.9 stamps, 1 pack of $2.4 stamps and y packs of $1.4 stamps. Each pack contains 10 pieces of stamps. Write an inequality

    2 packs of $1.9 2 $1.9 10 = $381 pack of $2.4 1 $2.4 10 = $24y packs of $1.4 y $1.4 10 = $14yTotal value $38+$24+$14yThe inequality is $38+$24+$14y

  • Ronald HUIP.166 Question 13b: Find the value of y if the total value of the stamps that Mike has is $76.

    Total value $38+$24+$14yThe equation is $38+$24+$14y = $76or 14y+62 = 76 14y = 14 y = 1Therefore, y = 1.or Mike has one pack of $1.4 stamps.

    Ronald HUI

  • Ronald HUISome special terms:One half = One third = One quarter / One fourth = One fifth =

    First, Second, Third, Fourth, Fifth, Sixth, Seventh, Eighth, Ninth, Tenth, Eleventh, Twelfth, Thirteenth, Fourteenth,

    Ronald HUI

  • Page 165 of Textbook 1AQuestions 1 - 8Page 77 of WB 1A HomeworkQuestions 1 - 4

  • Ronald HUIA formula is an equation withAt least 1 variables on the right of equal sign.Only 1 variable (Subject) on the left of equal sign.

    e.g. A = (U + L) H 2A is the subject of the formulaU, L and H are the variables of the formula

    Do you know what this formula means?

    Ronald HUI

  • Ronald HUIP.169 Question 18: v = u + gt (u = -8, g = 10, t = 3, v = ?)

    v = u + gt = (-8) + (10) (3) Method of substitution = -8 + 30 = 22

    Ronald HUI

  • Ronald HUIP.169 Question 20: In the formula S=88+0.5t , if S=120, find the value of t.

    S = 88 + 0.5t (120) = 88 + 0.5t 120 - 88 = 0.5t 32 = 0.5t 32 2 = t 64 = tt = 64

    Ronald HUI

  • Ronald HUIP.169 Question 22a: It is given that V=Ah3. If V = 40 and h = 6, find the value of A.

    V = Ah 3 (40) = A (6) 3 40 3 = 6A 120 = 6A 120 6 = A 20 = A A = 20

    Ronald HUI

  • Ronald HUIP.169 Question 22b: It is given that V=Ah3. Find the value of h such that A = 5 and the value of V is half of that given in (a)

    In (a), V = 40. So, in (b), V = 20.V = Ah 3 (20) = (5) h 3 20 3 = 5h 60 = 5h 60 5 = h h = 12

    Ronald HUI

  • Page 169 of Textbook 1AQuestions 5 - 14Pages 80-81 of WB 1A HomeworkQuestions 1 - 5

  • Ronald HUIConsider a sequence: 2, 4, 6, 8, 10,

    Can you guess what are the next numbers?What is the 10th term?What is the 100th term?What is the nth term?

    1, 2, 3, 4, 5, , 10, , 100, , n ()2, 4, 6, 8, 10, , 20, , 200, , 2n ()

    Ronald HUI

  • Ronald HUIA Sequence is a group of numbers with number pattern.Each number in the sequence is called a Term.The first one in the sequence is called the First Term.

    In the sequence, 2, 4, 6, 8, 10, 2 is the first term, 4 is the 2nd term, 6 is The general term () is 2n or an=2n

    Ronald HUI

  • Ronald HUIWhat is the NEXT TWO terms of the following sequences?

    4, 8, 12, 16, 20, 12, 24, 36, 48, 60, -1, -2, -3, -4, -5, 5, 6, 7, 8, 9, 6, 8, 10, 12, 14, -20, -10, 0, 10, 20,

    Ronald HUI

  • Ronald HUIWhat is the GENERAL terms of the following sequences?

    4, 8, 12, 16, 20, 12, 24, 36, 48, 60, -1, -2, -3, -4, -5, 5, 6, 7, 8, 9, 6, 8, 10, 12, 14, -20, -10, 0, 10, 20,

    Ronald HUI

  • Ronald HUIGiven a general term: an=2n-1What is the first 5 terms?The first 5 terms are:a1 = 2(1)-1 = 1a2 = 2(2)-1 = 3a3 = 2(3)-1 = 5a4 = 2(4)-1 = 7a5 = 2(5)-1 = 9What is the 17th term?The 17th term is a17 = 2(17)-1 = 33

    Ronald HUI

  • Pages 83 - 84 of WB 1AQuestions 1 - 4Page 175 of Textbook 1AQuestions 1 - 12

  • Folder13 Nov (Tuesday)WB (P.77, 80, 81)13 Nov (Tuesday)SHW (III) (Chapter 4)14 Nov (Wednesday)Open Book Quiz (Chapter 4)14 Nov (Wednesday)Close Book Quiz (Chapter 4)21 Nov (Wednesday)You must hand in on time!

  • Good Luck!

    Enjoy the world of Mathematics!Ronald HUI

    Ronald HUI