Expresswala Academy Mathematics Tuition

Simple Equations using Integers

Question paper, Set 2

  • Set 2 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+53=16x + 53 = 16.
    1 mark
    Answer and solution

    x+53=16x + 53 = 16

    ⇒x=16−53\Rightarrow x = 16 - 53

    ⇒x=−37\Rightarrow x = -37

    Answer: x=−37x = -37

  2. Solve x−63=−74x - 63 = -74.
    1 mark
    Answer and solution

    x−63=−74x - 63 = -74

    ⇒x=−74+63\Rightarrow x = -74 + 63

    ⇒x=−11\Rightarrow x = -11

    Answer: x=−11x = -11

  3. Solve x×4=320x \times 4 = 320.
    1 mark
    Answer and solution

    x×4=320x \times 4 = 320

    ⇒x=3204\displaystyle \Rightarrow x = \frac{320}{4}

    ⇒x=80\Rightarrow x = 80

    Answer: x=80x = 80

  4. Solve x5=45\displaystyle \frac{x}{5} = 45.
    1 mark
    Answer and solution

    x5=45\displaystyle \frac{x}{5} = 45

    ⇒x=45×5\Rightarrow x = 45 \times 5

    ⇒x=225\Rightarrow x = 225

    Answer: x=225x = 225

  5. Solve: (i) x+54=−52x + 54 = -52 (ii) x−84=−88x - 84 = -88 (iii) 5×x=1855 \times x = 185 (iv) x22=130\displaystyle \frac{x}{22} = 130
    5 marks
    Answer and solution

    (i) x+54=−52x + 54 = -52

    ⇒x=−52−54\Rightarrow x = -52 - 54

    ⇒x=−106\Rightarrow x = -106

    (ii) x−84=−88x - 84 = -88

    ⇒x=−88+84\Rightarrow x = -88 + 84

    ⇒x=−4\Rightarrow x = -4

    (iii) 5×x=1855 \times x = 185

    ⇒x=1855\displaystyle \Rightarrow x = \frac{185}{5}

    ⇒x=37\Rightarrow x = 37

    (iv) x22=130\displaystyle \frac{x}{22} = 130

    ⇒x=130×22\Rightarrow x = 130 \times 22

    ⇒x=2860\Rightarrow x = 2860

    Answer: (i) x=−106x = -106, (ii) x=−4x = -4, (iii) x=37x = 37, (iv) x=2860x = 2860

  6. Solve x−401=−597x - 401 = -597.
    1 mark
    Answer and solution

    x−401=−597x - 401 = -597

    ⇒x=−597+401\Rightarrow x = -597 + 401

    Column subtraction: 597−401=196597 - 401 = 196; the bigger number is negative, so xx is negative

    ⇒x=−196\Rightarrow x = -196

    Answer: x=−196x = -196

  7. If x×16=14512x \times 16 = 14512, then find xx.
    2 marks
    Answer and solution

    x×16=14512x \times 16 = 14512

    ⇒x=1451216\displaystyle \Rightarrow x = \frac{14512}{16}

    Long division: 145÷16=9145 \div 16 = 9, remainder 11; 11÷16=011 \div 16 = 0, remainder 1111; 112÷16=7112 \div 16 = 7, remainder 00

    ⇒x=907\Rightarrow x = 907

    Answer: x=907x = 907

  8. Find xx if x2=−66\displaystyle \frac{x}{2} = -66.
    1 mark
    Answer and solution

    x2=−66\displaystyle \frac{x}{2} = -66

    ⇒x=(−66)×2\Rightarrow x = (-66) \times 2

    −×+=−- \times + = -

    ⇒x=−132\Rightarrow x = -132

    Answer: x=−132x = -132

  9. Solve 4x+133=−34x + 133 = -3.
    2 marks
    Answer and solution

    4x+133=−34x + 133 = -3

    ⇒4x=−3−133\Rightarrow 4x = -3 - 133

    ⇒4x=−136\Rightarrow 4x = -136

    ⇒x=−1364\displaystyle \Rightarrow x = \frac{-136}{4}

    ⇒x=−34\Rightarrow x = -34

    Answer: x=−34x = -34

  10. If x3+100=90\displaystyle \frac{x}{3} + 100 = 90, then find xx.
    3 marks
    Answer and solution

    x3+100=90\displaystyle \frac{x}{3} + 100 = 90

    ⇒x3=90−100\displaystyle \Rightarrow \frac{x}{3} = 90 - 100

    ⇒x3=−10\displaystyle \Rightarrow \frac{x}{3} = -10

    ⇒x=−10×3\Rightarrow x = -10 \times 3

    ⇒x=−30\Rightarrow x = -30

    Answer: x=−30x = -30

  11. Solve: (i) 9x2+3=102\displaystyle \frac{9x}{2} + 3 = 102 (ii) 8x5−36=−92\displaystyle \frac{8x}{5} - 36 = -92
    5 marks
    Answer and solution

    (i) 9x2+3=102\displaystyle \frac{9x}{2} + 3 = 102

    ⇒9x2=102−3\displaystyle \Rightarrow \frac{9x}{2} = 102 - 3

    ⇒9x2=99\displaystyle \Rightarrow \frac{9x}{2} = 99

    ⇒9x=99×2\Rightarrow 9x = 99 \times 2

    ⇒9x=198\Rightarrow 9x = 198

    ⇒x=1989\displaystyle \Rightarrow x = \frac{198}{9}

    ⇒x=22\Rightarrow x = 22

    (ii) 8x5−36=−92\displaystyle \frac{8x}{5} - 36 = -92

    ⇒8x5=−92+36\displaystyle \Rightarrow \frac{8x}{5} = -92 + 36

    ⇒8x5=−56\displaystyle \Rightarrow \frac{8x}{5} = -56

    ⇒8x=−56×5\Rightarrow 8x = -56 \times 5

    ⇒8x=−280\Rightarrow 8x = -280

    ⇒x=−2808\displaystyle \Rightarrow x = \frac{-280}{8}

    ⇒x=−35\Rightarrow x = -35

    Answer: (i) x=22x = 22, (ii) x=−35x = -35

  12. Solve x+23=49−xx + 23 = 49 - x.
    2 marks
    Answer and solution

    x+23=49−xx + 23 = 49 - x

    ⇒x+x=49−23\Rightarrow x + x = 49 - 23

    ⇒2x=26\Rightarrow 2x = 26

    ⇒x=262\displaystyle \Rightarrow x = \frac{26}{2}

    ⇒x=13\Rightarrow x = 13

    Answer: x=13x = 13

  13. If 6x+3=93−3x6x + 3 = 93 - 3x, then find xx.
    3 marks
    Answer and solution

    6x+3=93−3x6x + 3 = 93 - 3x

    ⇒6x+3x=93−3\Rightarrow 6x + 3x = 93 - 3

    ⇒9x=90\Rightarrow 9x = 90

    ⇒x=909\displaystyle \Rightarrow x = \frac{90}{9}

    ⇒x=10\Rightarrow x = 10

    Answer: x=10x = 10

  14. If 5x−23+4x=−41+7x5x - 23 + 4x = -41 + 7x, then find xx.
    3 marks
    Answer and solution

    5x−23+4x=−41+7x5x - 23 + 4x = -41 + 7x

    ⇒9x−23=−41+7x\Rightarrow 9x - 23 = -41 + 7x

    ⇒9x−7x=−41+23\Rightarrow 9x - 7x = -41 + 23

    ⇒2x=−18\Rightarrow 2x = -18

    ⇒x=−182\displaystyle \Rightarrow x = \frac{-18}{2}

    ⇒x=−9\Rightarrow x = -9

    Answer: x=−9x = -9

  15. If 23−9x=−10323 - 9x = -103, then find xx.
    2 marks
    Answer and solution

    23−9x=−10323 - 9x = -103

    ⇒−9x=−103−23\Rightarrow -9x = -103 - 23

    ⇒−9x=−126\Rightarrow -9x = -126

    ⇒x=−126−9\displaystyle \Rightarrow x = \frac{-126}{-9}

    (−÷−=+)(- \div - = +)

    ⇒x=14\Rightarrow x = 14

    Answer: x=14x = 14

  16. Solve: (i) 3x−139=−84+4x3x - 139 = -84 + 4x (ii) −3x+13−6x=4-3x + 13 - 6x = 4
    5 marks
    Answer and solution

    (i) 3x−139=−84+4x3x - 139 = -84 + 4x

    ⇒3x−4x=−84+139\Rightarrow 3x - 4x = -84 + 139

    ⇒(−1)x=55\Rightarrow (-1)x = 55

    ⇒x=55−1\displaystyle \Rightarrow x = \frac{55}{-1}

    (+÷−=−)(+ \div - = -)

    ⇒x=−55\Rightarrow x = -55

    (ii) −3x+13−6x=4-3x + 13 - 6x = 4

    ⇒−9x+13=4\Rightarrow -9x + 13 = 4

    ⇒−9x=4−13\Rightarrow -9x = 4 - 13

    ⇒−9x=−9\Rightarrow -9x = -9

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

    (−÷−=+)(- \div - = +)

    ⇒x=1\Rightarrow x = 1

    Answer: (i) x=−55x = -55, (ii) x=1x = 1

  17. The sum of two integers is −840-840. If one of them is −121-121, then find the other.
    2 marks
    Answer and solution

    Let the other integer be xx.

    x+(−121)=−840x + (-121) = -840

    ⇒x=−840−(−121)\Rightarrow x = -840 - (-121)

    ⇒x=−840+121\Rightarrow x = -840 + 121

    ⇒x=−719\Rightarrow x = -719

    Answer: −719-719

  18. What number should be added to −202-202 to get 258258?
    2 marks
    Answer and solution

    Let the number be xx.

    −202+x=258-202 + x = 258

    ⇒x=258−(−202)\Rightarrow x = 258 - (-202)

    ⇒x=258+202\Rightarrow x = 258 + 202

    ⇒x=460\Rightarrow x = 460

    Answer: 460460

  19. What number should be subtracted from −15-15 to get −129-129?
    3 marks
    Answer and solution

    Let the number be xx.

    −15−x=−129-15 - x = -129

    ⇒−x=−129+15\Rightarrow -x = -129 + 15

    ⇒−x=−114\Rightarrow -x = -114

    ⇒x=114\Rightarrow x = 114

    Answer: 114114

  20. (i) The product of two integers is −444-444. If one of them is −12-12, then find the other. (ii) The difference of two integers is 8181. If the smaller of them is 6060, find the larger.
    5 marks
    Answer and solution

    (i) Let the other integer be xx.

    x×(−12)=−444x \times (-12) = -444

    ⇒x=−444−12\displaystyle \Rightarrow x = \frac{-444}{-12}

    Long division: 44÷12=344 \div 12 = 3, remainder 88; 84÷12=784 \div 12 = 7, remainder 00

    (−÷−=+)(- \div - = +)

    ⇒x=37\Rightarrow x = 37

    (ii) Let the larger integer be xx.

    Larger −- smaller == difference

    x−60=81x - 60 = 81

    ⇒x=81+60\Rightarrow x = 81 + 60

    ⇒x=141\Rightarrow x = 141

    Answer: (i) 3737, (ii) 141141