Answer: AD/CD = 2/5
Step-by-step explanation:
Triangle ABC is similar to triangle DEC on the basis of AA(Angle angle)
Recall, if 2 triangles are similar, it means that the ratio of their corresponding sides are equal. Thus,
AB/DE = BC/EC = AC/DC
From the information given,
AB/DE = 7/5
Thus,
AC/DC = 7/5
AD + CD = AC
(AD + CD)/DC = 7/5
AD/DC + CD/DC = 7/5
AD/DC + 1 = 7/5
AD/DC = 7/5 - 1
AD/DC = 2/5
AD/CD = 2/5