Expresswala Academy Mathematics Tuition

Simple Equations using Integers

Question paper, Set 3

  • Set 3 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+48=−41x + 48 = -41.
    1 mark
    Answer and solution

    x+48=−41x + 48 = -41

    ⇒x=−41−48\Rightarrow x = -41 - 48

    ⇒x=−89\Rightarrow x = -89

    Answer: x=−89x = -89

  2. Solve x−12=−64x - 12 = -64.
    1 mark
    Answer and solution

    x−12=−64x - 12 = -64

    ⇒x=−64+12\Rightarrow x = -64 + 12

    ⇒x=−52\Rightarrow x = -52

    Answer: x=−52x = -52

  3. Solve x×4=340x \times 4 = 340.
    1 mark
    Answer and solution

    x×4=340x \times 4 = 340

    ⇒x=3404\displaystyle \Rightarrow x = \frac{340}{4}

    ⇒x=85\Rightarrow x = 85

    Answer: x=85x = 85

  4. Find xx if x3=49\displaystyle \frac{x}{3} = 49.
    1 mark
    Answer and solution

    x3=49\displaystyle \frac{x}{3} = 49

    ⇒x=49×3\Rightarrow x = 49 \times 3

    ⇒x=147\Rightarrow x = 147

    Answer: x=147x = 147

  5. Solve: (i) x+19=−51x + 19 = -51 (ii) x−45=−36x - 45 = -36 (iii) x×6=594x \times 6 = 594 (iv) x19=798\displaystyle \frac{x}{19} = 798
    5 marks
    Answer and solution

    (i) x+19=−51x + 19 = -51

    ⇒x=−51−19\Rightarrow x = -51 - 19

    ⇒x=−70\Rightarrow x = -70

    (ii) x−45=−36x - 45 = -36

    ⇒x=−36+45\Rightarrow x = -36 + 45

    ⇒x=9\Rightarrow x = 9

    (iii) x×6=594x \times 6 = 594

    ⇒x=5946\displaystyle \Rightarrow x = \frac{594}{6}

    ⇒x=99\Rightarrow x = 99

    (iv) x19=798\displaystyle \frac{x}{19} = 798

    ⇒x=798×19\Rightarrow x = 798 \times 19

    ⇒x=15162\Rightarrow x = 15162

    Answer: (i) x=−70x = -70, (ii) x=9x = 9, (iii) x=99x = 99, (iv) x=15162x = 15162

  6. If x+55904=154551x + 55904 = 154551, then find xx.
    1 mark
    Answer and solution

    x+55904=154551x + 55904 = 154551

    ⇒x=154551−55904\Rightarrow x = 154551 - 55904

    Column subtraction: 154551−55904=98647154551 - 55904 = 98647

    ⇒x=98647\Rightarrow x = 98647

    Answer: x=98647x = 98647

  7. If x×22=19998x \times 22 = 19998, then find xx.
    2 marks
    Answer and solution

    x×22=19998x \times 22 = 19998

    ⇒x=1999822\displaystyle \Rightarrow x = \frac{19998}{22}

    Long division: 199÷22=9199 \div 22 = 9, remainder 11; 19÷22=019 \div 22 = 0, remainder 1919; 198÷22=9198 \div 22 = 9, remainder 00

    ⇒x=909\Rightarrow x = 909

    Answer: x=909x = 909

  8. Find xx if x−2=31\displaystyle \frac{x}{-2} = 31.
    1 mark
    Answer and solution

    x−2=31\displaystyle \frac{x}{-2} = 31

    ⇒x=31×(−2)\Rightarrow x = 31 \times (-2)

    +×−=−+ \times - = -

    ⇒x=−62\Rightarrow x = -62

    Answer: x=−62x = -62

  9. Solve 5x−95=955x - 95 = 95.
    2 marks
    Answer and solution

    5x−95=955x - 95 = 95

    ⇒5x=95+95\Rightarrow 5x = 95 + 95

    ⇒5x=190\Rightarrow 5x = 190

    ⇒x=1905\displaystyle \Rightarrow x = \frac{190}{5}

    ⇒x=38\Rightarrow x = 38

    Answer: x=38x = 38

  10. If x3+25=39\displaystyle \frac{x}{3} + 25 = 39, then find xx.
    3 marks
    Answer and solution

    x3+25=39\displaystyle \frac{x}{3} + 25 = 39

    ⇒x3=39−25\displaystyle \Rightarrow \frac{x}{3} = 39 - 25

    ⇒x3=14\displaystyle \Rightarrow \frac{x}{3} = 14

    ⇒x=14×3\Rightarrow x = 14 \times 3

    ⇒x=42\Rightarrow x = 42

    Answer: x=42x = 42

  11. Solve: (i) 8x9+22=78\displaystyle \frac{8x}{9} + 22 = 78 (ii) 3x4−24=−3\displaystyle \frac{3x}{4} - 24 = -3
    5 marks
    Answer and solution

    (i) 8x9+22=78\displaystyle \frac{8x}{9} + 22 = 78

    ⇒8x9=78−22\displaystyle \Rightarrow \frac{8x}{9} = 78 - 22

    ⇒8x9=56\displaystyle \Rightarrow \frac{8x}{9} = 56

    ⇒8x=56×9\Rightarrow 8x = 56 \times 9

    ⇒8x=504\Rightarrow 8x = 504

    ⇒x=5048\displaystyle \Rightarrow x = \frac{504}{8}

    ⇒x=63\Rightarrow x = 63

    (ii) 3x4−24=−3\displaystyle \frac{3x}{4} - 24 = -3

    ⇒3x4=−3+24\displaystyle \Rightarrow \frac{3x}{4} = -3 + 24

    ⇒3x4=21\displaystyle \Rightarrow \frac{3x}{4} = 21

    ⇒3x=21×4\Rightarrow 3x = 21 \times 4

    ⇒3x=84\Rightarrow 3x = 84

    ⇒x=843\displaystyle \Rightarrow x = \frac{84}{3}

    ⇒x=28\Rightarrow x = 28

    Answer: (i) x=63x = 63, (ii) x=28x = 28

  12. Find xx if x+31=−23−xx + 31 = -23 - x.
    2 marks
    Answer and solution

    x+31=−23−xx + 31 = -23 - x

    ⇒x+x=−23−31\Rightarrow x + x = -23 - 31

    ⇒2x=−54\Rightarrow 2x = -54

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

    ⇒x=−27\Rightarrow x = -27

    Answer: x=−27x = -27

  13. Find xx if 6x+24=−106−7x6x + 24 = -106 - 7x.
    3 marks
    Answer and solution

    6x+24=−106−7x6x + 24 = -106 - 7x

    ⇒6x+7x=−106−24\Rightarrow 6x + 7x = -106 - 24

    ⇒13x=−130\Rightarrow 13x = -130

    ⇒x=−13013\displaystyle \Rightarrow x = \frac{-130}{13}

    ⇒x=−10\Rightarrow x = -10

    Answer: x=−10x = -10

  14. Find xx if 7x+30+2x=54+6x7x + 30 + 2x = 54 + 6x.
    3 marks
    Answer and solution

    7x+30+2x=54+6x7x + 30 + 2x = 54 + 6x

    ⇒9x+30=54+6x\Rightarrow 9x + 30 = 54 + 6x

    ⇒9x−6x=54−30\Rightarrow 9x - 6x = 54 - 30

    ⇒3x=24\Rightarrow 3x = 24

    ⇒x=243\displaystyle \Rightarrow x = \frac{24}{3}

    ⇒x=8\Rightarrow x = 8

    Answer: x=8x = 8

  15. If 55−6x=3155 - 6x = 31, then find xx.
    2 marks
    Answer and solution

    55−6x=3155 - 6x = 31

    ⇒−6x=31−55\Rightarrow -6x = 31 - 55

    ⇒−6x=−24\Rightarrow -6x = -24

    ⇒x=−24−6\displaystyle \Rightarrow x = \frac{-24}{-6}

    (−÷−=+)(- \div - = +)

    ⇒x=4\Rightarrow x = 4

    Answer: x=4x = 4

  16. Solve: (i) 7x−62=−86+9x7x - 62 = -86 + 9x (ii) −12x+11−5x=130-12x + 11 - 5x = 130
    5 marks
    Answer and solution

    (i) 7x−62=−86+9x7x - 62 = -86 + 9x

    ⇒7x−9x=−86+62\Rightarrow 7x - 9x = -86 + 62

    ⇒−2x=−24\Rightarrow -2x = -24

    ⇒x=−24−2\displaystyle \Rightarrow x = \frac{-24}{-2}

    (−÷−=+)(- \div - = +)

    ⇒x=12\Rightarrow x = 12

    (ii) −12x+11−5x=130-12x + 11 - 5x = 130

    ⇒−17x+11=130\Rightarrow -17x + 11 = 130

    ⇒−17x=130−11\Rightarrow -17x = 130 - 11

    ⇒−17x=119\Rightarrow -17x = 119

    ⇒x=119−17\displaystyle \Rightarrow x = \frac{119}{-17}

    (+÷−=−)(+ \div - = -)

    ⇒x=−7\Rightarrow x = -7

    Answer: (i) x=12x = 12, (ii) x=−7x = -7

  17. The sum of two integers is 554554. If one of them is 956956, then find the other.
    2 marks
    Answer and solution

    Let the other integer be xx.

    x+956=554x + 956 = 554

    ⇒x=554−956\Rightarrow x = 554 - 956

    ⇒x=−402\Rightarrow x = -402

    Answer: −402-402

  18. What number should be added to 112112 to get −152-152?
    2 marks
    Answer and solution

    Let the number be xx.

    112+x=−152112 + x = -152

    ⇒x=−152−112\Rightarrow x = -152 - 112

    ⇒x=−264\Rightarrow x = -264

    Answer: −264-264

  19. What number should be subtracted from 142142 to get 194194?
    3 marks
    Answer and solution

    Let the number be xx.

    142−x=194142 - x = 194

    ⇒−x=194−142\Rightarrow -x = 194 - 142

    ⇒−x=52\Rightarrow -x = 52

    ⇒x=−52\Rightarrow x = -52

    Answer: −52-52

  20. (i) The product of two integers is −936-936. If one of them is −18-18, then find the other. (ii) The difference of two integers is 7474. If the larger of them is −104-104, find the smaller.
    5 marks
    Answer and solution

    (i) Let the other integer be xx.

    x×(−18)=−936x \times (-18) = -936

    ⇒x=−936−18\displaystyle \Rightarrow x = \frac{-936}{-18}

    Long division: 93÷18=593 \div 18 = 5, remainder 33; 36÷18=236 \div 18 = 2, remainder 00

    (−÷−=+)(- \div - = +)

    ⇒x=52\Rightarrow x = 52

    (ii) Let the smaller integer be xx.

    Larger −- smaller == difference

    −104−x=74-104 - x = 74

    ⇒−x=74+104\Rightarrow -x = 74 + 104

    ⇒−x=178\Rightarrow -x = 178

    ⇒x=−178\Rightarrow x = -178

    Answer: (i) 5252, (ii) −178-178