Linda is 𝑚 years old, and her sibling is nine years younger. Write an expression in the simplest form that represents the sum of their ages.
So we need Linda’s age plus her sibling’s age. Linda’s age can be represented by 𝑚. And the sibling’s age, who’s nine years younger, can be represented by 𝑚 minus nine.
In order to simplify, we need to combine like terms. We should combine the 𝑚s. 𝑚 plus 𝑚 is equal to two 𝑚. And we bring down the minus nine.
Therefore, two 𝑚 minus nine is the expression, in the simplest form, that represents the sum of their ages.