Rosalinda examined the angles at right and wrote the equation below.  

$(2x+1º)+(x-10º)=90º$

1. Does her equation make sense? If so, explain why her equation must be true. If it is not correct, determine what is incorrect and write the equation.

   Hint (a):

   Is a right angle (as illustrated above), equal to $90º$?

   Answer (a):

   Yes. This means Rosalinda's equation makes sense, because the two angles make up a $90º$ angle.

2. If you have not already done so, solve her equation, clearly showing all your steps. What are the measures of the two angles?

   Hint (b):

   Simplify without the parentheses and combine like terms.  Then solve for $x$. One of the angles is $x-10$. The other is $2x+1$. The sum of the two angles is $90$.

3. Verify that your answer is correct.

   Hint (c):

   After solving for $x$, substitute your answer into the original equation to verify it is correct.