Question 1165722
<br>
The number: n<br>
Double the number: 2n<br>
Ten subtracted from double the number: 2n-10<br>
If you are just starting to learn algebra, note that you need to pay attention to what the words say.  Beginning students often look at the numbers themselves without paying attention to the meaning of the words.  In that phrase, the "ten" comes before "double the number"; so often students will write "10-2n" instead of "2n-10".  But clearly the meaning is that the ten is subtracted from double the number, so the correct expression is 2n-10.<br>
Now write the equation that says "nine is equal to ten subtracted from double a number":<br>
9 = 2n-10<br>
And now, if you had been asked to solve the problem, you are ready to do so using basic algebra.