Factorise the quadratic equation: x^2 + 5x + 6 = 0 and hence find the two solutions to the equation.

  1. Start by writing the equation out again: x2 + 5x + 6 = 0

  2. I do it by thinking which two numbers add together to = 5 and which same two numbers multiply to = 6. The answer to this is 2 and 3.

  3. So the next step is to write the eqaution down in factorised form (there is no need to do any other thinking about the numbers to go inside the brackets becuase the coefficient of x2 is 1).

  4. So we now have: (x + 2)(x + 3) = 0 - This is the answer to the first part of the question.

  5. To get the answer to the second part, one of the two brackets must = 0 (because if two numbers multiplied together = 0, one number must = 0).

  6. So either x + 2 = 0, in which case x = -2, or x + 3 = 0 in which case x = -3. This is the answer to the second part.

7.To check, substitute these number back into the original equation: (-2)2 + 5(-2) + 6 = 4 - 10 + 6 = 0 (correct) (-3)2 + 5(-3) + 6 = 9 - 15 + 6 = 0 (correct)

Answered by Callum J. Maths tutor

7072 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Use completing the square to find the minimum of y = x^2 - 4x + 8


An ice cream cone with a base 4.5 cm in diameter and whose height is 10 cm is filled with ice cream. What is the volume of ice cream to 3 d.p.? If the density of ice cream is 1095 kg/m^3, what is the mass of ice cream in 5 cones to 3 s.f.?


A and B are two points. Point A has coordinates (–2, 4). Point B has coordinates (8, 9). C is the midpoint of the line segment AB. Find the coordinates of C


Solve the quadratic equation x^2 + 7x + 6 = 0


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