Question 916621: A billboard is 10 feet longer than it is high. The billboard has 336 square feet of advertising space. What are the dimensions of the billboard?
Answer by kmadison(20)   (Show Source):
You can put this solution on YOUR website! Let B represent the base of the billboard and H represent its' height. From the problem we know that 
Then using common knowledge, we know that standard billboards are rectangular in shape. Therefore, the relationship of B and H to the Area, represented by A is: 
We have 2 equations, and 2 unknowns. We can plug the height equation into our area equation to get:  or  This is a simple quadratic equation, therefore we can use the quadratic formula  to find B, where a = 1, b = 10, c = -336.
The solutions to this are 14 and -24. Since we know these types of quantities cannot be negative, we take the positive root, 14, meaning the base is 24 ft and the height is 14 ft. To check this we simply compute 24*14 and we find it does indeed equal 336, the area of the advertising space.
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