SAT官方每日一题附答案和解析[数学](2018年10月24日)
日期:2018-10-24 09:35
(单词翻译:单击)
每日一题
Mathematics
ax+5=4x-3
In the linear equation shown above, a is a constant. If the equation has no solution, what is the value of a?
A.1
B.2
C.3
D.4
答案和解析
答案:D
解析:
Choice D is correct. A linear equation in one variable will have no solution if the equation reduces to an equation of the form: ax+b=cx+d, where a=c and b≠d.
Therefore, if a=4, the equation 4x+5=4x-3 yields 5=-3. This is not true for any values of x, and therefore this value of a results in an equation with no solutions.
重点单词