Problem
ALG-B1-M03-P004 A Specified Root
#4
★☆☆☆☆ Level 1 of 5
Find \(a\) if \(x=3\) is a root of \(x^2-ax+12=0\).
Substitute \(x=3\) into the equation.
We get \(9-3a+12=0\), so \(21-3a=0\).
Therefore \(a=7\).
The parameter is determined by the root condition.