If x^2 + 2y = -14 and y = 4x + 1 , by using the quadratic formula, find the possible values for x.

First the equation for y must be substituted into the first equation to give a quadratic equation in x. Rearrange this equation so that the left-hand side equals 0. Using the quadratic formula the possible values for x can be found to be x = -4.

Answered by Rachael W. Maths tutor

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