Problema Solution

The product of two consecutive integers is 420. Which quadratic equation can be used to find x, the lesser number?

Answer provided by our tutors

If 'x' is the lesser number then the other consecutive number is 'x + 1'.

The product is 420:

x(x + 1) = 420

x^2 + x = 420

x^2 + x - 420 = 0 is the quadratic equation we need to solve to find x

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click here to see the equation solved for x

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x1 = 20

x2 = - 21

There are two solutions:

First solution is: 20 and 21

Second solution is: -21 and -20