Acv2idn
Answered

Sumali sa IDNStudy.com at makakuha ng maraming kaalaman. Hanapin ang mga solusyong kailangan mo nang mabilis at tiyak sa tulong ng aming mga bihasang miyembro.

The sum of the ages of Dorothy and Dorileen is 41.In 5 years Dorothy will be twice as old as Dorileen.Find their ages 3 years ago.(Algebraic expressions and equations)









Sagot :

x + y = 41
y = 41-x

Present Ages:
Dorothy's age: x
Dorileen's age: 41-x

Ages in 5 years (add 5):  
Dorothy:  x + 5
Dorileen:  41 - x + 5  = (41+5) - x = 46 - x

Equation:  In five years, Dorothy will be twice as old as Dorileen
x + 5 = 2(46 - x)
x + 5 = 92 - 2x
2x + x = 92 - 5
3x = 87
3x/3 = 87/3
x = 29

Substitute x with 29:
Present ages:
Dorothy: x = 29 years old
Dorileen:  41 - x   ⇒   41 - 29 = 12 years old

FINAL ANSWER:
Ages 3 years ago (less 3):
Dorothy: 29-3 = 26 years old
Dorileen:  12 - 3 = 9 years old.