If using the method of completing the square to solve the quadratic equation x^2-4x+10=0,which number would have to be added to “complete the square”?

4

Step-by-step explanation:

Given

x² - 4x + 10 = 0

subtract 10 from both sides

x² - 4x = - 10

To complete the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(- 2)x + 4 = - 10 + 4

(x - 2)² = - 6

To complete the square add 4

i think it is everything has to equal 180 so, if i correct 4=c. 6=d. 8=a. 7=b. and the last question would be c. because they are parallel lines and they are congruent.

step-by-step explanation:

the reason everything has to equal to 180 is because that is how it works. i'm guessing that is its rule. 4 and 8 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 6 and 7 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 60+60 is 180. so, now you have your answer