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MCQ

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15 questions · auto-graded multiple-choice test.

MCQ 11 Mark
Tick $(\checkmark)$ the correct answer: $(x+5)(x-3)=?$
  • A
    $x^2+5 x-15$
  • B
    $x^2-3 x-15$
  • C
    $x^2+2 x+15$
  • $x^2+2 x-15$
Answer
Correct option: D.
$x^2+2 x-15$
$(x+5)(x-3)$
$(x)^2+(5-3) x+5 \times(-3)$
$=x^2+2 x-15$
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MCQ 21 Mark
Tick $(\checkmark)$ the correct answer: If $\Big(\text{x}+\frac{1}{\text{x}}\Big)=5,$ then $\Big(\text{x}^2+\frac{1}{\text{x}^2}\Big)=?$
  • A
    $25$
  • B
    $27$
  • $23$
  • D
    $25\frac{1}{25}$
Answer
Correct option: C.
$23$
$\Big(\text{x}+\frac{1}{\text{x}}\Big)=5,$
$\Big(\text{x}+\frac{1}{\text{x}}\Big)^2=(5)^2$
$\Rightarrow​​\text{x}^2+\frac{1}{\text{x}^2}+2=25$
$\Rightarrow​​\text{x}^2+\frac{1}{\text{x}^2}+25-2=23$
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MCQ 31 Mark
Tick $(\checkmark)$ the correct answer: $\left(2 x^2+3 x+1\right) \div(x+1)=?$
  • A
    $(x+1)$
  • $(2 x+1)$
  • C
    $(x+3)$
  • D
    $(2 x+3)$
Answer
Correct option: B.
$(2 x+1)$
$(2 x+1)$
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MCQ 41 Mark
Tick $(\checkmark)$ the correct answer: $\left(2 x^2+3 x+1\right) \div(x+1)=?$
  • A
    $(x+1)$
  • $(2 x+1)$
  • C
    $(x+3)$
  • D
    $(2 x+3)$
Answer
Correct option: B.
$(2 x+1)$
$(2 x+1)$
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MCQ 51 Mark
Tick $(\checkmark)$ the correct answer: $8 a^2 b^3 \div(-2 a b)=?$
  • A
    $4 a b^2$
  • B
    $4 a^2 b$
  • $-4 a b^2$
  • D
    $-4 a^2 b$
Answer
Correct option: C.
$-4 a b^2$
$8 a^2 b^3 \div(-2 a b)$
$\Rightarrow \frac{8 a^2 b^3}{-2 a b}$
$\Rightarrow-4 a^{2-1} b^{3-1}$
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MCQ 61 Mark
Tick $(\checkmark)$ the correct answer:
If $(a-b)=7$ and $a b=9$, then $\left(a^2+b^2\right)= ?$
  • $67$
  • B
    $31$
  • C
    $40$
  • D
    $58$
Answer
Correct option: A.
$67$
$a-b=7$
$a b=9$
$a^2+b^2=(a-b)^2+2 a b$
$=(7)^2+2 \times 9$
$=49+18$
$=67$
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MCQ 71 Mark
Tick $(\checkmark)$ the correct answer:
$(82)^2-(18)^2=$ ?
 
  • A
    $8218$
  • B
    $6418$
  • $6400$
  • D
    $7204$
Answer
Correct option: C.
$6400$
$(82)^2-(18)^2$
$=(82+18)(82-18)$
$=100 \times 64$
$=6400$

 
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MCQ 81 Mark
Tick $(\checkmark)$ the correct answer: If $\Big(\text{x}-\frac{1}{\text{x}}\Big)=6,$ then $\Big(\text{x}^2+\frac{1}{\text{x}^2}\Big)=?$
  • A
    $36$
  • $38$
  • C
    $32$
  • D
    $36\frac{1}{36}$
Answer
Correct option: B.
$38$
$\Big(\text{x}-\frac{1}{\text{x}}\Big)=6,$
Squaring on both sides
$\Big(\text{x}-\frac{1}{\text{x}}\Big)^2=(6)^2$
$\Rightarrow​​\text{x}^2+\frac{1}{\text{x}^2}-2=36$
$\Rightarrow​​\text{x}^2+\frac{1}{\text{x}^2}=36+2=38$
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MCQ 91 Mark
Tick $(\checkmark)$ the correct answer:
$\left(3 q+7 p^2-2 r^3+4\right)-\left(4 p^2-2 q+7 r^3-3\right)=?$
  • A
    $\left(p^2+2 q+5 r^3+1\right)$
  • B
    $\left(11 p^2+q+5 r^3+1\right)$
  • C
    $\left(-3 p^2-5 q+9 r^3-7\right)$
  • $\left(3 p^2+5 q-9 r^3+7\right)$
Answer
Correct option: D.
$\left(3 p^2+5 q-9 r^3+7\right)$
$\left(3 q+7 p^2-2 r^3+4\right)-\left(4 p^2-2 q+7 r^3-3\right)$
$=3 q+7 p^2-2 r^3+4-4 p^2+2 q-7 r^3+3$
$=5 q+3 p^2-9 r^3+7$
$=3 p^2+5 q-9 r^3+7$
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MCQ 101 Mark
Tick $(\checkmark)$ the correct answer:
$(a+1)(a-1)\left(a^2+1\right)=?$
  • A
    $\left(a^4-2 a^2-1\right)$
  • B
    $\left(a^4-a^2-1\right)$
  • $\left(a^4-1\right)$
  • D
    $\left(a^4+1\right)$
Answer
Correct option: C.
$\left(a^4-1\right)$
$(a+1)(a-1)\left(a^2+1\right)$
$=\left(a^2-1\right)\left(a^2+1\right)$
$=a^4-1$
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MCQ 111 Mark
Tick $(\checkmark)$ the correct answer: $(2 x+5)(2 x-5)=?$
  • A
    $\left(4 x ^2+25\right)$
  • $\left(4 x^2-25\right)$
  • C
    $\left(4 x^2-10 x+25\right)$
  • D
    $\left(4 x^2+10 x-25\right)$
Answer
Correct option: B.
$\left(4 x^2-25\right)$
$(2 x+5)(2 x-5)$
$=(2 x)^2-(5)^2$
$=4 x^2-25$
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MCQ 121 Mark
Tick $(\checkmark)$ the correct answer:
If $x=10$, then the value of $\left(4 x^2+20 x+25\right)=$ ?
  • A
    $256$
  • B
    $425$
  • $625$
  • D
    $575$
Answer
Correct option: C.
$625$
$x=10$
$=\left(4 x^2+20 x+25\right)$
$=(2 x)^2+2 \times 2 x \times 5+(5)^2$
$=(2 x+5)^2$
$=(2 \times 10+5)^2$
$=(20+5)^2$
$=(25)^2$
$=625$
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MCQ 131 Mark
Tick $(\checkmark)$ the correct answer:
$(2 x+3)(3 x-1)=?$
  • A
    $\left(6 x^2+8 x-3\right)$
  • $\left(6 x^2+7 x-3\right)$
  • C
    $6 x^2-7 x-3$
  • D
    $\left(6 x^2-7 x+3\right)$
Answer
Correct option: B.
$\left(6 x^2+7 x-3\right)$
$(2 x+3)(3 x-1)$
$=6 x^2-2 x+9 x-3$
$=6 x^2+7 x-3$
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MCQ 141 Mark
Tick $(\checkmark)$ the correct answer:
$(197 \times 203)=\text { ? }$
  • $39991$
  • B
    $39999$
  • C
    $40009$
  • D
    $40001$
Answer
Correct option: A.
$39991$
$(197 \times 203)$
$=(200-3)(200+3)$
$=(200)^2-(3)^2$
$=40000-9$
$​​​​​=39991$
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MCQ 151 Mark
Tick $(\checkmark)$ the correct answer: $\Big(\frac{1}{\text{x}}+\frac{1}{\text{y}}\Big)\Big(\frac{1}{\text{x}}-\frac{1}{\text{y}}\Big)=?$
  • A
    $\Big(\frac{1}{\text{x}^2}-\frac{1}{\text{y}2}\Big)$
  • $\Big(\frac{1}{\text{x}^2}+\frac{1}{\text{y}2}\Big)$
  • C
    $\Big(\frac{1}{\text{x}^2}+\frac{1}{\text{y}^2}-\frac{1}{\text{xy}}\Big)$
  • D
    $\Big(\frac{1}{\text{x}^2}-\frac{1}{\text{y}^2}+\frac{1}{\text{xy}}\Big)$
Answer
Correct option: B.
$\Big(\frac{1}{\text{x}^2}+\frac{1}{\text{y}2}\Big)$
$\Big(\frac{1}{\text{x}}+\frac{1}{\text{y}}\Big)\Big(\frac{1}{\text{x}}-\frac{1}{\text{y}}\Big)$
$=\Big(\frac{1}{\text{x}}\Big)^2-\Big(\frac{1}{\text{y}}\Big)^2$
$=\frac{1}{\text{x}^2}-\frac{1}{\text{y}^2}$
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