\

The sentence is “Twenty five is 10 less than a number”

Let n be the number

The word less than indicates subtraction, and the symbol is

Thus, the numerical expression is “”

The equation is \ \

Addition property of equality: If a = b then a + c = b + c.

        (Add 10 to both sides)

                  (Additive inverse property: )

                        (Additive identity: )

                                (Add: )

The value of the expression is 35.