Tabitha is 30 years old. This is 5 less than 7 times her son's age.

Question

I have to translate it into an equation then find the number.

Answer 1

T = Tabitha 

S = Son

 

T = 30

 

30 = 7S - 5

 

30 + 5 = 7S

 

35 = 7S

 

35/7 = S

 

5 = S

Answer 2

Since we don't know her son's age, we define a variable for the son's age.

 

Let x = son's age

 

 

Now we can write an equation that represents Tabitha's age in terms of x.

 

Tabitha's age = 7x - 5

 

 

We do know Tabitha's age.  She is 30 years old.  Plug that number into the equation so you can solve for x.

 

30 = 7x - 5

 

 

Add 5 on both sides of the equation.

 

35 = 7x

 

 

Divide both sides of the equation by 7.

 

5 = x

 

 

Her son is 5 years old.