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

Answer: Option A

Explanation:

• A. 3
• B. -3
• C. 7
• D. 9

Answer: Option B

Explanation:

• A. $\frac{x\left(x+1\right)\left(2x+1\right)}{6}$
• B. $\frac{x\left(x+1\right)}{2}$
• C. $x$
• D. ${\left\{\frac{x\left(x+y\right)}{2}\right\}}^2$

Answer: Option A

Explanation:

• A. $a^2+b^2$
• B. $a^2-b^2$
• C. ${(a+b)}^3$
• D. ${(a-b)}^3$

Answer: Option D

Explanation:

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

Answer: Option A

Explanation:

• A. 1
• B. 2
• C. -1
• D. -2

Answer: Option C

Explanation:

• 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. (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. 0.001
• B. 0.01
• C. 0.1
• D. 1.0

Answer: Option C

Explanation:

• A. $\frac{1}{80}$
• B. $\frac{1}{800}$
• C. $\frac{1}{8000}$
• D. $\frac{1}{8}$

Answer: Option D

Explanation:

• A. (6 - a)(4a - 1)
• B. (a - 6)(4a + 1)
• C. (a - b)(4a - 1)
• D. (6 - a)(4a + 1)

Answer: Option D

Explanation:

• A. $-1$
• B. $-2$
• C. $-3$
• D. $-4$

Answer: Option C

Explanation: