AMC12 2002 B

AMC12 2002 B · Q2

AMC12 2002 B · Q2. It mainly tests Manipulating equations.

What is the value of $(3x - 2)(4x + 1) - (3x - 2)4x + 1$ when $x=4$?

当 $x=4$ 时，$(3x - 2)(4x + 1) - (3x - 2)4x + 1$ 的值是多少？

(A) 0 0

(B) 1 1

(D) 11 11

(E) 12 12

Answer

Correct choice: (D)

正确答案：（D）

Solution

By the distributive property, \[(3x-2)[(4x+1)-4x] + 1 = 3x-2 + 1 = 3x-1 = 3(4) - 1 = \boxed{\mathrm{(D)}\ 11}\].

由分配律， \[(3x-2)[(4x+1)-4x] + 1 = 3x-2 + 1 = 3x-1 = 3(4) - 1 = \boxed{\mathrm{(D)}\ 11}\].

Topics