Concept:A number in base x is expanded using powers of x.Explanation:Write 23x in expanded form: 2x+3.Write 325 in expanded form: 3×5+2=15+2=17.Set the two expressions equal: 2x+3=17.Subtract 3 from both sides: 2x=14.Divide both sides by 2: x=7.Answer:x=7, which is option A.