Question

x^2 - 10x + 21 factorize the following by completing squares ​

Answer 1

Answer:

7,3

Step-by-step explanation:

let,x^2-10x+k=(x+a)^2

=x^2+2ax +a^2

comparing the terms,

-10x=2ax

-5 =a

k=a^2

k=-5^2

=25

now,

x^2-10x+25-25+21=0

(x^2-10x+25)-25+21=0

(x-5)^2-4=0

(x-5)^2=4

x-5=+-2 (taking Square root)

x=5+2 or x=5-2

=7 =3