How do you solve #x^2 + 2x = 8# by completing the square?
1 Answer
Just take 8 on the other side and get started!
Explanation:
Well, as i said take 8 to other side;
Now,
for completing the square method,here are the steps you apply to every quadratic equation mostly:
(1) First multiply the coefficient of
In this case its : (-8*1)=-8
(2) Now break this term in such a way that the sum or difference of those breaked terms give you the coefficient of the term which has x and the multiplication of those terms give you the original term.
In this case its: 4 ans -2 because the multiplication of these two terms gives you 8 (4*-2=-8) and the sum of these two terms gives you the coefficient of the term containing x i.e. 2 (4-2=2).
(3) Now write the equation with those terms, in the form of x.
In this case:
(4). Now take common such that the terms inside the bracket are same :
In this case:
which reveals the same equation.
(5). now write the bracket terms in one bracket and combine the terms outside in one bracket.
In this case:
Hence the answer is this and thus the roots are 2,-4.
:)
