Question #0415a

2 Answers
Nov 3, 2017

x=-4 and -2

Explanation:

x^2+6x+8=0

=>x^2+2x+4x+8=0

=>x(x+2)+4(x+2)=0

=>(x+4)(x+2)=0

Using the zero product property (if a*b=0, then a=0 and b=0)

:.x+4=0 and x+2 = 0

:.x=-4and-2

Nov 3, 2017

x=-4 or x= -2

Explanation:

x ^2 + 6x + 8 = 0

Find two such numbers whose sum is coefficient of middle term, i.e. 6, and product is product of coefficient of first term and last term, i.e. 8:

Two such numbers are 4 and 2. So rewrite and solve the above equation as:

x ^2 +2x + 4x + 8 = 0

x(x+2) + 4(x+2) = 0

=> (x+4)(x+2)= 0--------- factorised form.

therefore (x+4)= 0 => x= -4
0r
(x+2) = 0 => x= -2

Answer : x=-4 or x= -2