Building equations from words

Jonathon is two years older than Stephen. The sum of their ages is 30. Find Stephen's age.

Lets call Stephen's age "x". Now if Jonathon is two years older he must be x + 2 years old.
Now the sum of their ages is 30. So if I add the ages of both boys I will get 30.
Ok, time to construct our equation so we can solve it.

Stephen's age + Jonathon's age = 30
x + (x + 2) = 30
Next step is to expand the brackets and collect like terms.
x + x + 2 = 30
2x + 2 = 30

Using bactracking or cacooning we solve the equation for x.
Subtract 2 from both sides
2x + 2 - 2 = 30 - 2
2x = 28
divide both sides by 2
2x/2 = 28/2
x = 14
Worded exercise
Equation
Solution
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Solutions