Question

use completion of sq method
1.x^2-x-2=0
2.x^2+x-6=0
3.x^2-7x+5=0
4.x^2-8x-9=0
5.x^2+3x+8=0​

Answer 1

Answer:

I am so sorry I am in grade 6 so I do not know this

Answer 2

Step-by-step explanation:

I will solve one for u rest please do it by same method urself

x²-x-2 = 0

1st step take the constant term on R. H. S we get

x²-x= 2

2nd step to make the coefficient of x² 1 as the coeff. of x² is already one so we can move to 3rd step

3rd step

multiply coefficient of x by 1/2 ( note do not included -sign in it) = 1/2

4th step now add and subtract the square of this no we get

x²-x+(1/2) ²-(1/2) ²= 2

as x²-x+ 1/2² is in the form of a²+b²-2ab we can write it as (x-1/2) ²

so

(x-1/2) ² = 2+(1/2) ² ( by taking -1/2² in R. H. S.)

(x-1/2) ² = 2+1/4

( x-1/2) ²= 9/4

square rooting on both side we get

(x-1/2) = +-√9/4

x-1/2 =+- 3/2

taking + part we get

x= 3/2+1/2 = 4/2 = 2

taking - part we get

-3/2+1/2

= -2/2 = -1