Molly is 4 years older than Jane. The sum of their ages is 20. How old is Jane? Write an equation

Question

Molly is 4 years older than Jane. The sum of their ages is 20. How old is Jane? Write an equation.

Answer 1

m: Molly's age

j: Jane's age

 

m=j+4

m+j=20

 

j+4+j=20

2j+4=20

2j=16

j=8

Answer 2

Say, Jane is x years old.

Molly will be. x+4 years old

So , the equation is

x+x+4=20

x=8 years 

Jane is 8 years old.