SOLUTION: 2. What is the area in square feet of a room that is (4x - 3) feet wide and (2x - 7) feet long?

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: 2. What is the area in square feet of a room that is (4x - 3) feet wide and (2x - 7) feet long?       Log On


   

Question 171923: 2. What is the area in square feet of a room that is (4x - 3) feet wide and (2x - 7) feet long?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Area = Width * Length


So in this case, the area is A=%284x+-+3%29%282x+-+7%29


Now let's FOIL the expression %284x+-+3%29%282x+-+7%29


Remember, when you FOIL an expression, you follow this procedure:


%28highlight%284x%29-3%29%28highlight%282x%29-7%29 Multiply the First terms:%284%2Ax%29%2A%282%2Ax%29=8%2Ax%5E2.


%28highlight%284x%29-3%29%282x%2Bhighlight%28-7%29%29 Multiply the Outer terms:%284%2Ax%29%2A%28-7%29=-28%2Ax.


%284x%2Bhighlight%28-3%29%29%28highlight%282x%29-7%29 Multiply the Inner terms:%28-3%29%2A%282%2Ax%29=-6%2Ax.


%284x%2Bhighlight%28-3%29%29%282x%2Bhighlight%28-7%29%29 Multiply the Last terms:%28-3%29%2A%28-7%29=21.


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8%2Ax%5E2-28%2Ax-6%2Ax%2B21 Now collect every term to make a single expression.


8%2Ax%5E2-34%2Ax%2B21 Now combine like terms.


So %284x-3%29%282x-7%29 FOILs to 8%2Ax%5E2-34%2Ax%2B21.


In other words, %284x-3%29%282x-7%29=8%2Ax%5E2-34%2Ax%2B21.


So the area is A=8x%5E2-34x%2B21 square feet.