Question 983388
Notice how the last term of 5x^2 + 19x + 12 is 12


The constant term of 5x+4 is 4.


Divide: 12/4 = 3


So the constant term in the length must be 3.


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The first term in the area expression is 5x^2. The first term in the width is 5x. Divide: 5x^2 over 5x = x


So the variable term must be just x.


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The length is (x+3)


(x+3)*(5x+4) = 5x^2 + 19x + 12