Bihar School Examination Board (BSEB) Class 8 Mathematics: Algebraic Expressions and Identities

Instructions. Answer all questions. Fill exactly one bubble per question on the OMR sheet.

1. Algebraic Expressions and Identities

   1.

   What is the result of adding the algebraic expressions $(3x^2 + 5x - 7)$ and $(2x^2 - 3x + 1)$?

   1. (A)

      $5x^2 + 2x - 6$

   2. (B)

      $5x^2 - 2x + 6$

   3. (C)

      $5x^2 + 8x - 8$

   4. (D)

      $x^2 + 2x - 6$

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   Answer: (A)

   $5x^2 + 2x - 6$

   To add the expressions, combine like terms: $(3x^2 + 2x^2) = 5x^2$, $(5x - 3x) = 2x$, and $(-7 + 1) = -6$.

   Algebraic Expressions and Identities · Easy

2. 2.

   Subtract $(4a - 3b + 2c)$ from $(6a + 5b - c)$.

   1. (A)

      $2a - 8b + 3c$

   2. (B)

      $10a + 2b + c$

   3. (C)

      $2a + 2b + c$

   4. (D)

      $2a + 8b - 3c$

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   Answer: (D)

   $2a + 8b - 3c$

   Subtracting $(4a - 3b + 2c)$ from $(6a + 5b - c)$ means $(6a + 5b - c) - (4a - 3b + 2c)$. Distribute the negative sign: $6a + 5b - c - 4a + 3b - 2c$. Combine like terms: $(6a - 4a) = 2a$, $(5b + 3b) = 8b$, and $(-c - 2c) = -3c$.

   Algebraic Expressions and Identities · Medium

3. 3.

   Find the product of $(2x + 3)$ and $(x - 4)$.

   1. (A)

      $2x^2 - 11x - 12$

   2. (B)

      $2x^2 + 5x - 12$

   3. (C)

      $2x^2 - x - 12$

   4. (D)

      $2x^2 - 5x - 12$

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   Answer: (D)

   $2x^2 - 5x - 12$

   Using the FOIL method: First terms: $(2x)(x) = 2x^2$. Outer terms: $(2x)(-4) = -8x$. Inner terms: $(3)(x) = 3x$. Last terms: $(3)(-4) = -12$. Combining them gives $2x^2 - 8x + 3x - 12 = 2x^2 - 5x - 12$.

   Algebraic Expressions and Identities · Medium

— End of the paper · updated 14 October 2026 —