Solving a Quadratic Equation by Completing the Square
Question 1iii...
Question
Question 1(iii)
Find the roots of the following quadratic equations by factorisation:
(iii) √2x2+7x+5√2=0
Open in App
Solution
(iii) √2x2+7x+5√2 =√2x2+5x+2x+5√2(Splitting the middle term 7x as 5x+2x because 5x×2x=10x2) =x(√2x+5)+√2(√2x+5)=(√2x+5)(x+√2)
Roots of this equation are the values for which (√2x+5)(x+√2)=0 ∴√2x+5=0orx+√2=0 ⇒x=−5√2orx=−√2