208k views
2 votes
What equation results from completing the square and then factoring?

x2 - 8x = 39
O A. (x-8)2 = 55
O B. (X-8)2 = 23
O C. (x-4)2 = 23
O D. (x-4)2 = 55

2 Answers

5 votes

Answer: the answer is D

Explanation:

User Umer Abbas
by
6.5k points
2 votes

Answer:


\large\boxed{D.\ (x-4)^2=55}

Explanation:


(a-b)^2=a^2-2ab+b^2\qquad(*)\\\\\\x^2-8x=39\\\\x^2-2(x)(4)=39\qquad\text{add}\ 4^2=16\ \text{to both sides}\\\\\underbrace{x^2-2(x)(4)+4^2}_((*))=39+16\\\\(x-4)^2=55

User Shengchalover
by
5.4k points