The total of three sis ages of 39 Diana half as old as Michelle and three years younger than Juliet create a equatiosolve it to determinethe age of each sister

Question

its a practice question to help me study for a test I have tomorrow related to linear equation and inequalities 

Answer 1

Let d = Diana's age

Let m = Michelle's age

Let j = Juliet's age

 

d+m+j = 39   Their ages total 39

d = m/2         Diana is half Michelle's age

d = j-3           Diana is 3 years younger than Juliet

 

m/2 = j-3 ...

m = 2(j-3) = 2j-6

 

In 1st equation replace d with j-3 and

replace m with 2j-6

 

(j-3) + (2j-6) + j = 39

4j - 9 = 39

4j + 48

j = 12

 

d = j-3 = 9

m = 2j-6 = 24-6 = 18

 

Diana is 9

Juliet is 12

Michelle is 18