in 13 years a child will be 6 years older than twice her current age, what is her current age ?

Question

how do you figure this problem out ? Do you have to use a certain formula or use this in an equation

Answer 1

Let x=the child's current age

 

The equation becomes:

 

2x+6=x+13 Note: The right side of the equation indicates 13 has to be added to her current age to be consistent with what will be her age in 13 years in which is equal to 2x+6.

 

The key to solving this equation is to isolate the variables on one side and put the constant on the other side.

 

Subtract x and 6 from both sides of the equation in which is:

 

2x-x+6-6=x-x+13-6. This implies x=7 years old.