When you're solving an equation, there are three possibilities. Two of which are chosen if your statement is true or not.
If you're able to get x alone, there is one solution. However, If all of the variables are eliminated and you're left with a false statement, that will be <u>no solution</u>. Example: 1=5? False.
If all of the variables are eliminated and you're left with a true statement, that solution is <u>all real numbers</u>. Example: 5=5? True.
The area of the whole rectangle is 91cm. Subtract 2 because of what is not shaded in the bottom right, then subtract 12 from what is not shaded in the top left. That leaves you with 77cm of shaded area.