Complete the square and solve. Show all work.

x2 + 4x = 5

Question

Complete the square and solve.  Show all work. 

x2 + 4x = 5

anonymous · Answer

I need help @amistre64 @Hero @Muzzack

amistre64 · Answer

completing the square is just a matter of determing how to make a perfect square.

all a perfect square is, is taking some item and squaring it.

(x+a)^2 ,  when we expand this out we get:  x^2 + 2a x + a^2

notice the relationship between the middle and last coefficients ...
               
if we take the middle coeff, divide it by 2, and square it we get the last term

          (2a/2)^2 = a^2

this is key.  you are asked to find a number that will be a^2 in order to 'complete' the setup and turn it into a perfect square

amistre64 · Answer

lets just find 'a' :)

2a = 4 when a = ?  therefore what is a^2?

anonymous · Answer

a = 1?

anonymous · Answer

@amistre64

amistre64 · Answer

not quite

2a = 4

2(1) isnot 4

anonymous · Answer

a = 2!!  @amistre64