How do I solve a quadratic equation by competing the square?

How would you solve  x2+8x+16=81Show that this can be factorised (x+4)2=92Which can then be easily solved by square rooting both sides
What if we could now use this method to solve all quadratics?!!?
Consider Solve  x2+6x+1=0
We can complete the square by:(x+3)2-9+1=0 (x+3)2-8=0 (x+3)2=8 (x+3)=±√8 x=-3±2√2

Related Maths GCSE answers

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Simplify the equation below:


How do you calculate a^5 x a^16 / a^4?


Work out the value of n, the value of A & the value of B (question given below in correct subscript)


(e*sqrt(e))/cuberoot(e^2)=e^k find k


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