Problema Solution

The product of some negative number and 4 less than twice that number is 240. Find the number.

Answer provided by our tutors

Let 'x' represent the unknown negative number, x< 0.

x*(2x - 4) = 240

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click here to see the above quadratic equation solved

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Since x is negative, we only need the negative root of the equation, that is:

x = -10

Indeed:

(-10)*(2*(-10) - 4) = (-10)(-24) = 240

The unknown number is -10.