Question

Which expression is equivalent to (3x^2-7)?

Answer 1

Answer:

C. $(10x^2-4)-(7x^2+3)$

Step-by-step explanation:

In option A,

$(2x^2-11)-(x^2+4)= 2x^2 - 11 - x^2 - 4 = x^2 -15$

Since,

$(x^2-15)\neq (3x^2-7)$

⇒ Option A is incorrect.

In option B,

$(5x^2-6)-(2x^2-1)= 5x^2-6-2x^2+1 = 3x^2 -5$

Since,

$(3x^2-5)\neq (3x^2-7)$

⇒ Option B is incorrect.

In option C,

$(10x^2-4)-(7x^2+3)= 10x^2-4-7x^2-3 = 3x^2 -7$

⇒ Option C is correct.

In option D,

$(15x^2-8)-(18x^2+1)= 15x^2-8-18x^2-1= -3x^2 -9$

Since,

$(-3x^2 -9)\neq (3x^2-7)$

⇒ Option D is incorrect.

Answer 2

$C.\ (10x^2-4)-(7x^2+3)=10x^2-4-7x^2-3=(10x^2-7x^2)+(-4-3)=3x^2-7$