AMC12 2005 A

AMC12 2005 A · Q2

AMC12 2005 A · Q2. It mainly tests Linear equations, Word problems (algebra).

The equations $2x + 7 = 3$ and $bx - 10 = -2$ have the same solution $x$. What is the value of $b$?

方程 $2x + 7 = 3$ 和 $bx - 10 = -2$ 有相同的解 $x$。$b$ 的值是多少？

(A) -8 -8

(B) -4 -4

(D) 4 4

(E) 8 8

Answer

Correct choice: (B)

正确答案：（B）

Solution

$2x + 7 = 3 \iff x = -2$, so we require $-2b-10 = -2 \iff -2b = 8 \iff b = \boxed{\textbf{(B) } -4}$.

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