Question

To solve the equation for x by completing the square what equation is equivalent to x^2-x-2=0
here are options for both blanks (The equivalent equation (x-Blank)^2=Blank

-1/4
1/4
-1/2
1/2
-9/4
9/4
-3/2
3/2

Answer 1

so to complete the square in
ax^2+bx+c=d form

make sure a=1
subtract c from both sides
take 1/2 of b and square it
add that to both sides
factor perfect square

1x^2-1x-2=0
a=1
move c to other side
add 2 to oth sides
x^2-1x=2
take 1/2 of b and square it
1/2 of -1=-1/2
squaer it
1/4
add that to both sides
x^2-1x+1/4=2+1/4
factor left side
(x-1/2)=2+1/4

first blank is 1/2

2+1/4=8/4+1/4=9/4

blanks are
1/2 and 9/4