• A. $1$
• B. $x$
• C. $\left(1-x\right)$
• D. $\left(1+x\right)$

Answer: Option D

Explanation:

• A. ${\left(-1\right)}^{r}r{x}^r$
• B. $\left(r+1\right)x^{r+1}$
• C. $\left(r+1\right)x^r$
• D. ${\left(-1\right)}^r\left(r+1\right)x^r$

Answer: Option D

Explanation:

• A. $\left(1+a+b\right)\left(1-a+b\right)$
• B. $\left(1+a+b\right)\left(1-a-b\right)$
• C. $\left(1+a+b\right)\left(1+a-b\right)$
• D. $\left(1+a-b\right)\left(1-a+b\right)$

Answer: Option D

Explanation:

• A. (1+a+b)(1-a+b)
• B. (1+a+b)(1-a-b)
• C. (1+a+b)(1+a-b)
• D. (1+a-b)(1-a+b)

Answer: Option D

Explanation:

• A. $\left(1+a-b\right)\left(1-a+b\right)$
• B. $\left(1+a+b\right)\left(1-a+b\right)$
• C. $\left(1+a+b\right)\left(1-a-b\right)$
• D. $\left(1-a+b\right)\left(1-a-b\right)$

Answer: Option A

Explanation:

• A. $-2<x<1$
• B. $-1<x<0$
• C. $0<x<1$
• D. $-1<x<1$

Answer: Option C

Explanation:

• A. $-\frac{1}{a}$
• B. -1
• D. $\frac{1}{a}$

Answer: Option C

Explanation:

• A. $x\left(x-1\right)$
• B. $\frac{x\left(x+1\right)}{2}$
• C. $x\left(x+1\right)$
• D. $x^2$

Answer: Option D

Explanation:

• A. 253
• B. 254
• C. 256
• D. 258

Answer: Option A

Explanation:

• A. 210
• B. 212
• C. 214
• D. 220

Answer: Option A

Explanation:

• A. 168
• B. 171
• C. 174
• D. 176

Answer: Option B

Explanation:

• A. $\sqrt{2}$
• B. $4$
• C. $\sqrt{3}$
• D. $2\sqrt{1}$

Answer: Option B

Explanation:

• A. $\sqrt{2}$
• B. $4$
• C. $\sqrt{3}$
• D. $2\sqrt{1}$

Answer: Option B

Explanation:

• A. $x=\frac{\pi }{6}$
• B. $x=\frac{-3\pi }{2}$
• C. $x=\frac{\pi }{2}$
• D. $x=0$

Answer: Option A

Explanation:

• A. ১
• B. অনির্ণেয়
• C. ০.০
• D. ০

Answer: Option B

Explanation: