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2566 . $x^{4} - x - 1 = 0$ হলে, $x - \frac{1}{x^{2}} =$ কত ? ..

B. 1
C. 2
D. 4

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Answer: Option B

Explanation:

2567 . m-n=x এবং mn = $6 x^{2}$ হলে $m^{3} - n^{3}$ = কত? ..

A. $19 x^{2}$
B. $19 x^{3}$
C. $18 x^{2}$
D. $18 x^{3}$

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Answer: Option B

Explanation:

m^{3} - n^{3 = {(m - n)}^{3} + 3 m n (m - n) = x^{3} + 3.6 x^{2} . x = x^{3} + 18 x^{3} = 19 x^{3}}

১৬ তম বেসরকারি প্রভাষক নিবন্ধন পরীক্ষা (30-08-2019)

A. 1 s
B. 1.5 s
C. 2 s
D. 3 s

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Answer: Option A

Explanation:

আন্ডারগ্র্যাজুয়েট প্রোগ্রাম ভর্তি পরীক্ষা || প্রযুক্তি ইউনিট (18-05-2024) ২০২৩-২০২৪ || ঢাকা বিশ্ববিদ্যালয় || 2024

A. px = qy
B. qx = py
C. xy = pq
D. qx + py = 0

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Answer: Option B

Explanation:

A. 2
B. 4
C. 6
D. 8

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Answer: Option C

Explanation:

2571 . $x^{2} + y^{2} + x^{2} = 5, x + y + z = 3$ হলে yz + zx -xy এর মান কত? ..

A. -5
B. -4
C. -3
D. -2

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Answer: Option D

Explanation:

2572 . $a^{4} - 51 a^{2} + 1 = 0$ হলে $a - \frac{1}{a}$ এর মান কত? ..

A. $\pm 9$
B. $\pm 7$
C. $\pm 5$
D. $\pm 3$

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Answer: Option B

Explanation:

দেওয়া আছে, a^{4} - 51 a^{2} + 1 = 0 \Rightarrow a^{4} + 1 = 51 a^{2} \Rightarrow \frac{a^{4} + 1}{a^{2}} = \frac{51 a^{2}}{a^{2}} \Rightarrow \frac{a^{4}}{a^{2}} + \frac{1}{a^{2}} = 51 \Rightarrow a^{2} + \frac{1}{a^{2}} = 51 এখন, {(a - \frac{1}{a})}^{2} = {(a + \frac{1}{a})}^{2} - 4 . a . \frac{1}{a} = a^{2} + 2 . a . \frac{1}{a} + \frac{1}{a^{2}} - 4 = a^{2} + \frac{1}{a^{2}} - 2 = 51 - 2 = 49 ∴ a - \frac{1}{a} = \sqrt{49} = \pm 7

2573 . $4 x^{2} - 2$ হতে কত বিয়োগ করলে রাশিটি পূর্ণবর্গ হবে? ..

A. $- \frac{1}{4 x^{2}}$
B. $- \frac{1}{2 x^{2}}$
C. $\frac{1}{4 x^{2}}$
D. $\frac{1}{2 x^{2}}$

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Answer: Option A

Explanation:

4 x^{2} - 2 = {(2 x)}^{2} - 2.2 x . \frac{1}{2 x} + {(\frac{1}{2 x})}^{2} - {(\frac{1}{2 x})}^{2} = {(2 x - \frac{1}{2 x})}^{2} - \frac{1}{4 x^{2}} {সুতরাং, 4x}^{2} -2 হতে - \frac{1}{4 x^{2}} বিয়োগ করলে রাশিটি পূর্ণবর্গ হবে। {(2 x - \frac{1}{2 x})}^{2} - \frac{1}{4 x^{2}} - (- \frac{1}{4 x^{2}}) = {(2 x - \frac{1}{2 x})}^{2} - \frac{1}{4 x^{2}} + \frac{1}{4 x^{2}} = {(2 x - \frac{1}{2 x})}^{2}

2574 . $\frac{a^{3} - b^{3}}{a + b}$ কে $\frac{a^{4} + b^{4} + a^{2} b^{2}}{a^{3} + b^{3}}$ দ্বারা ভাগ করলে ভাগফল কত হবে? ..

A. $a - b$
B. $a + b$
C. $a^{2} - b^{2}$
D. $a^{2} + b^{2}$

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Answer: Option A

Explanation:

\frac{a^{3} - b^{3}}{a + b} \div \frac{a^{4} + b^{4} + a^{2} b^{2}}{a^{3} + b^{3}} = \frac{(a - b) (a^{2} + a b + b^{2})}{a + b} \div \frac{{(a^{2})}^{2} + 2 . a^{2} . b^{2} + {(b^{2})}^{2} - {(a b)}^{2}}{(a + b) (a^{2} - a b + b^{2})} = \frac{(a - b) (a^{2} + a b + b^{2})}{a + b} \times \frac{(a + b) (a^{2} - a b + b^{2})}{{(a^{2} + b^{2})}^{2} - {(a b)}^{2}} = \frac{(a - b) (a^{2} + a b + b^{2})}{a + b} \times \frac{(a + b) (a^{2} - a b + b^{2})}{(a^{2} + b^{2} + a b) (a^{2} + b^{2} - a b)} = (a - b)

2575 . $x^{2} - 4 x + 1 = 0$ হলে $x \div (x^{2} - 3 x + 1)$ এর মান কত? ..

B. 1
C. 2
D. 4

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Answer: Option B

Explanation:

x² - 4x + 1 = 0

বা, x² + 1 = 4x

x/( x² - 3x + 1)

বা, x / 4x - 3x

∴x/x = 1

বাংলাদেশ পাবলিক সার্ভিস কমিশন (BPSC) || জুনিয়র ইন্সট্রাক্টর (18-03-2023) ||

2576 . $\frac{x}{y} + \frac{y}{x} = 6$ হলে $\frac{x^{2}}{y^{2}} + \frac{y^{2}}{x^{2}}$ এর মান কত? ..

A. 30
B. 32
C. 34
D. 36

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Answer: Option C

Explanation:

{(x/y) + (y + x)}² = 6²

= > (x²/y²) + 2.(x/y).(y/x) + (y²/x²) = 6²

= > (x²/y²) + (y²/x²) = 36 - 2 = 34

2577 . $x + \frac{1}{x} = 3$ হলে $x^{3} + \frac{1}{x^{3}}$ এর মান কত? ..

A. 16
B. 18
C. 22
D. 1

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Answer: Option B

Explanation:

দেওয়া আছে, x + \frac{1}{x} = 3 এখন, x^{3} + \frac{1}{x^{3}} = {(x + \frac{1}{x})}^{3} - 3 . x . \frac{1}{x} (x + \frac{1}{x}) = 3^{3} - 3.3 = 27 - 9 = 18

১৫ তম শিক্ষক নিবন্ধন পরীক্ষা (স্কুল সমপর্যায়-২) (19-04-2019)

2578 . x+y=8, xy==15 হলে ${(x - y)}^{4} = ?$ ..

A. 4
B. 8
C. 9
D. 16

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Answer: Option D

Explanation:

আমরা জানি, {(x - y)}^{2} = {(x + y)}^{2} - 4 x y = 8^{2} - 4 \times 15 = 64 - 60 = 4 ∴ x - y = 2 ∴ (x + y) + (x - y) = 8 + 2 \Rightarrow 2 x = 10 ∴ x = 5 ∴ y = 8 - 5 = 3 ∴ {(x - y)}^{4} = {(5 - 3)}^{4} = 2^{4} = 16

2579 . $5^{x} + 8 . 5^{x} + 16 . 5^{x} = 1$ হলে x এর মান কত? ..

A. -1
B. 3
C. -2
D. $- \frac{1}{2}$

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Answer: Option C

Explanation:

দেওয়া আছে, 5^{x} {+8×5}^{x} {+16×5}^{x} =1 \Rightarrow 5^{x} (1 + 8 + 16) = 1 \Rightarrow 5^{x} \times 25 = 1 \Rightarrow 5^{x} = \frac{1}{25} \Rightarrow 5^{x} = (\frac{1}{5^{2}}) \Rightarrow 5^{x} = 5^{- 2} ∴ x = - 2

2580 . $3^{- 3}$ এর মান কত ? ..

A. $\frac{1}{9}$
B. $\frac{1}{3}$
C. $\frac{1}{27}$
D. $\sqrt{3}$

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Answer: Option C

Explanation:

3^{- 3} = \frac{1}{3^{3}} = \frac{1}{27}

2569 . যদি (x, y), (p,q) এবং মূলবিন্দু সমরেখ হয়, তবে (If (x, y) (p,q) and the origin are collinear, then)

2570 . y = 3x x-অক্ষ এবং x = 2 দ্বারা সীমাবদ্ধ ক্ষেত্রের ক্ষেত্রফল (The area of the region enclosed by y = 3x x-axis and x = 2 is)

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