Problem:
The equations 2x+7=3 and bx−10=−2 have the same solution x. What is the value of b?
Answer Choices:
A. −8
B. −4
C. −2
D. 4
E. 8
Solution:
Since 2x+7=3 we have x=−2. Hence
−2=bx−10=−2b−10, so 2b=−8, and b=−4
Answer: B.
The problems on this page are the property of the MAA's American Mathematics Competitions