Solve x^2 +11x +30 = 0

This is what we call a quadratic equation. To solve, first we need to factorise this equation into two brackets. (x + _ )(x + _) =0To fill the brackets, we need to find 2 numbers that add to 11 and multiply to 30. Let's think about the factors of 30:30 and 115 and 2 10 and 3 5 and 6 Which of these pairs of factors adds to 11? 5 and 6 This gives us: x^2 +11x +30 = (x+5)(x+6) = 0Now, we need to solve. A quadratic equation will always have 2 solutions.(x+5)(x+6)=0 If we multiply 2 numbers together and get the answer 0, this means that at least one of the numbers must be 0. Therefore, x+5=0 and/or x+6=0Let's solve one at a time:x+5=0 We need x by itself on one side of the equation, so minus 5 from both sides of the equation: x= -5x+6=0Minus 6 from both sides of the equation:x=-6We have our 2 solutions: x=-5 and x=-6

HR
Answered by Holly R. Maths tutor

3842 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Find the difference between the areas of these 2 shapes to 2 decimal places. Rectangle (width 4cm length 2.5cm) Circle (diameter 2.4) use pi = 3.14


Make x the subject of the formula: y=(x+5w/2)^0.5


a.) simplify and expand (x+3)(2x+5) b.) differentiate (x+3)(2x+5) c.) where does this function intercept the x and y axis? d.) does this function have any turning points? if so where?


A ladder 6.8m long is leaning against a wall. The foot of the ladder is 1.5m from the wall. Calculate the distance the ladder reaches up the wall.


We're here to help

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

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences