Find the roots of the following quadratic equation: x^2 +2x -15 =0

The question asks for the roots, this simply means the numbers that could replace x in the equation and the result = 0. There are two ways too do this, firstly either using the Quadratic formula, or my factorising. This equation factors nicely and so we will use method 2 and saw the quadratic formula for more complex equations. You need to make sure the equation is in the form ax^2+ bx + c = 0, and from there your looking for two numbers that add to make b and multiply to make c. In this case 5 and -3. Then when we factoids we get (x+5) (x-3) = 0, meaning our factors are -5 and 3.

Related Maths A Level answers

All answers ▸

Find the inverse of f(x) = (3x - 6)/2


Explain the Principle of Moments.


Describe the set of transformations that will transformthe curve y=x^ to the curve y=x^2 + 4x - 1


the graph y = 3/((1-4x)*(1/2)) has a shaded region between x = 0 and x = 2, find area of the region


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences