Expresswala Academy Mathematics Tuition

Simple Equations using Integers

Question paper, Set 5

  • Set 5 of 10
  • 20 questions
  • 50 marks
  • 1 hour 30 minutes

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Work each question on paper first, then open its answer and solution to check your work.

  1. Find xx if x+71=−34x + 71 = -34.
    1 mark
    Answer and solution

    x+71=−34x + 71 = -34

    ⇒x=−34−71\Rightarrow x = -34 - 71

    ⇒x=−105\Rightarrow x = -105

    Answer: x=−105x = -105

  2. Solve x−48=−8x - 48 = -8.
    1 mark
    Answer and solution

    x−48=−8x - 48 = -8

    ⇒x=−8+48\Rightarrow x = -8 + 48

    ⇒x=40\Rightarrow x = 40

    Answer: x=40x = 40

  3. Solve 6×x=1986 \times x = 198.
    1 mark
    Answer and solution

    6×x=1986 \times x = 198

    ⇒x=1986\displaystyle \Rightarrow x = \frac{198}{6}

    ⇒x=33\Rightarrow x = 33

    Answer: x=33x = 33

  4. Find xx if x3=101\displaystyle \frac{x}{3} = 101.
    1 mark
    Answer and solution

    x3=101\displaystyle \frac{x}{3} = 101

    ⇒x=101×3\Rightarrow x = 101 \times 3

    ⇒x=303\Rightarrow x = 303

    Answer: x=303x = 303

  5. Solve: (i) x+65=−11x + 65 = -11 (ii) x−35=−56x - 35 = -56 (iii) 3×x=2133 \times x = 213 (iv) x16=820\displaystyle \frac{x}{16} = 820
    5 marks
    Answer and solution

    (i) x+65=−11x + 65 = -11

    ⇒x=−11−65\Rightarrow x = -11 - 65

    ⇒x=−76\Rightarrow x = -76

    (ii) x−35=−56x - 35 = -56

    ⇒x=−56+35\Rightarrow x = -56 + 35

    ⇒x=−21\Rightarrow x = -21

    (iii) 3×x=2133 \times x = 213

    ⇒x=2133\displaystyle \Rightarrow x = \frac{213}{3}

    ⇒x=71\Rightarrow x = 71

    (iv) x16=820\displaystyle \frac{x}{16} = 820

    ⇒x=820×16\Rightarrow x = 820 \times 16

    ⇒x=13120\Rightarrow x = 13120

    Answer: (i) x=−76x = -76, (ii) x=−21x = -21, (iii) x=71x = 71, (iv) x=13120x = 13120

  6. Find xx if x+98539=160411x + 98539 = 160411.
    1 mark
    Answer and solution

    x+98539=160411x + 98539 = 160411

    ⇒x=160411−98539\Rightarrow x = 160411 - 98539

    Column subtraction: 160411−98539=61872160411 - 98539 = 61872

    ⇒x=61872\Rightarrow x = 61872

    Answer: x=61872x = 61872

  7. Solve x×14=127204x \times 14 = 127204.
    2 marks
    Answer and solution

    x×14=127204x \times 14 = 127204

    ⇒x=12720414\displaystyle \Rightarrow x = \frac{127204}{14}

    Long division: 127÷14=9127 \div 14 = 9, remainder 11; 12÷14=012 \div 14 = 0, remainder 1212; 120÷14=8120 \div 14 = 8, remainder 88; 84÷14=684 \div 14 = 6, remainder 00

    ⇒x=9086\Rightarrow x = 9086

    Answer: x=9086x = 9086

  8. Find xx if x−6=39\displaystyle \frac{x}{-6} = 39.
    1 mark
    Answer and solution

    x−6=39\displaystyle \frac{x}{-6} = 39

    ⇒x=39×(−6)\Rightarrow x = 39 \times (-6)

    +×−=−+ \times - = -

    ⇒x=−234\Rightarrow x = -234

    Answer: x=−234x = -234

  9. If 4x+97=614x + 97 = 61, then find xx.
    2 marks
    Answer and solution

    4x+97=614x + 97 = 61

    ⇒4x=61−97\Rightarrow 4x = 61 - 97

    ⇒4x=−36\Rightarrow 4x = -36

    ⇒x=−364\displaystyle \Rightarrow x = \frac{-36}{4}

    ⇒x=−9\Rightarrow x = -9

    Answer: x=−9x = -9

  10. Solve x9−23=2\displaystyle \frac{x}{9} - 23 = 2.
    3 marks
    Answer and solution

    x9−23=2\displaystyle \frac{x}{9} - 23 = 2

    ⇒x9=2+23\displaystyle \Rightarrow \frac{x}{9} = 2 + 23

    ⇒x9=25\displaystyle \Rightarrow \frac{x}{9} = 25

    ⇒x=25×9\Rightarrow x = 25 \times 9

    ⇒x=225\Rightarrow x = 225

    Answer: x=225x = 225

  11. Solve: (i) 3x2+39=33\displaystyle \frac{3x}{2} + 39 = 33 (ii) 2x9−4=−10\displaystyle \frac{2x}{9} - 4 = -10
    5 marks
    Answer and solution

    (i) 3x2+39=33\displaystyle \frac{3x}{2} + 39 = 33

    ⇒3x2=33−39\displaystyle \Rightarrow \frac{3x}{2} = 33 - 39

    ⇒3x2=−6\displaystyle \Rightarrow \frac{3x}{2} = -6

    ⇒3x=−6×2\Rightarrow 3x = -6 \times 2

    ⇒3x=−12\Rightarrow 3x = -12

    ⇒x=−123\displaystyle \Rightarrow x = \frac{-12}{3}

    ⇒x=−4\Rightarrow x = -4

    (ii) 2x9−4=−10\displaystyle \frac{2x}{9} - 4 = -10

    ⇒2x9=−10+4\displaystyle \Rightarrow \frac{2x}{9} = -10 + 4

    ⇒2x9=−6\displaystyle \Rightarrow \frac{2x}{9} = -6

    ⇒2x=−6×9\Rightarrow 2x = -6 \times 9

    ⇒2x=−54\Rightarrow 2x = -54

    ⇒x=−542\displaystyle \Rightarrow x = \frac{-54}{2}

    ⇒x=−27\Rightarrow x = -27

    Answer: (i) x=−4x = -4, (ii) x=−27x = -27

  12. If x+38=32−xx + 38 = 32 - x, then find xx.
    2 marks
    Answer and solution

    x+38=32−xx + 38 = 32 - x

    ⇒x+x=32−38\Rightarrow x + x = 32 - 38

    ⇒2x=−6\Rightarrow 2x = -6

    ⇒x=−62\displaystyle \Rightarrow x = \frac{-6}{2}

    ⇒x=−3\Rightarrow x = -3

    Answer: x=−3x = -3

  13. Solve 2x−9=−81−7x2x - 9 = -81 - 7x.
    3 marks
    Answer and solution

    2x−9=−81−7x2x - 9 = -81 - 7x

    ⇒2x+7x=−81+9\Rightarrow 2x + 7x = -81 + 9

    ⇒9x=−72\Rightarrow 9x = -72

    ⇒x=−729\displaystyle \Rightarrow x = \frac{-72}{9}

    ⇒x=−8\Rightarrow x = -8

    Answer: x=−8x = -8

  14. Find xx if 6x−7+4x=−3+8x6x - 7 + 4x = -3 + 8x.
    3 marks
    Answer and solution

    6x−7+4x=−3+8x6x - 7 + 4x = -3 + 8x

    ⇒10x−7=−3+8x\Rightarrow 10x - 7 = -3 + 8x

    ⇒10x−8x=−3+7\Rightarrow 10x - 8x = -3 + 7

    ⇒2x=4\Rightarrow 2x = 4

    ⇒x=42\displaystyle \Rightarrow x = \frac{4}{2}

    ⇒x=2\Rightarrow x = 2

    Answer: x=2x = 2

  15. If 80−7x=−11680 - 7x = -116, then find xx.
    2 marks
    Answer and solution

    80−7x=−11680 - 7x = -116

    ⇒−7x=−116−80\Rightarrow -7x = -116 - 80

    ⇒−7x=−196\Rightarrow -7x = -196

    ⇒x=−196−7\displaystyle \Rightarrow x = \frac{-196}{-7}

    (−÷−=+)(- \div - = +)

    ⇒x=28\Rightarrow x = 28

    Answer: x=28x = 28

  16. Solve: (i) 9x−12=−92+11x9x - 12 = -92 + 11x (ii) −4x−9−8x=−21-4x - 9 - 8x = -21
    5 marks
    Answer and solution

    (i) 9x−12=−92+11x9x - 12 = -92 + 11x

    ⇒9x−11x=−92+12\Rightarrow 9x - 11x = -92 + 12

    ⇒−2x=−80\Rightarrow -2x = -80

    ⇒x=−80−2\displaystyle \Rightarrow x = \frac{-80}{-2}

    (−÷−=+)(- \div - = +)

    ⇒x=40\Rightarrow x = 40

    (ii) −4x−9−8x=−21-4x - 9 - 8x = -21

    ⇒−12x−9=−21\Rightarrow -12x - 9 = -21

    ⇒−12x=−21+9\Rightarrow -12x = -21 + 9

    ⇒−12x=−12\Rightarrow -12x = -12

    ⇒x=−12−12\displaystyle \Rightarrow x = \frac{-12}{-12}

    (−÷−=+)(- \div - = +)

    ⇒x=1\Rightarrow x = 1

    Answer: (i) x=40x = 40, (ii) x=1x = 1

  17. The sum of two integers is 266266. If one of them is 912912, then find the other.
    2 marks
    Answer and solution

    Let the other integer be xx.

    x+912=266x + 912 = 266

    ⇒x=266−912\Rightarrow x = 266 - 912

    ⇒x=−646\Rightarrow x = -646

    Answer: −646-646

  18. What number should be added to −254-254 to get 8383?
    2 marks
    Answer and solution

    Let the number be xx.

    −254+x=83-254 + x = 83

    ⇒x=83−(−254)\Rightarrow x = 83 - (-254)

    ⇒x=83+254\Rightarrow x = 83 + 254

    ⇒x=337\Rightarrow x = 337

    Answer: 337337

  19. What number should be subtracted from −101-101 to get 9191?
    3 marks
    Answer and solution

    Let the number be xx.

    −101−x=91-101 - x = 91

    ⇒−x=91+101\Rightarrow -x = 91 + 101

    ⇒−x=192\Rightarrow -x = 192

    ⇒x=−192\Rightarrow x = -192

    Answer: −192-192

  20. (i) The product of two integers is −1204-1204. If one of them is 2828, then find the other. (ii) The difference of two integers is 1515. If the larger of them is 9595, find the smaller.
    5 marks
    Answer and solution

    (i) Let the other integer be xx.

    x×28=−1204x \times 28 = -1204

    ⇒x=−120428\displaystyle \Rightarrow x = \frac{-1204}{28}

    Long division: 120÷28=4120 \div 28 = 4, remainder 88; 84÷28=384 \div 28 = 3, remainder 00

    (−÷+=−)(- \div + = -)

    ⇒x=−43\Rightarrow x = -43

    (ii) Let the smaller integer be xx.

    Larger −- smaller == difference

    95−x=1595 - x = 15

    ⇒−x=15−95\Rightarrow -x = 15 - 95

    ⇒−x=−80\Rightarrow -x = -80

    ⇒x=80\Rightarrow x = 80

    Answer: (i) −43-43, (ii) 8080