Question

x^2-2kx+49 is the square of a binomial. What is the possible value of k?

Answer 1

7

Answer 2

how do you solve that? Can you show your work pleazzz???

Answer 3

(x+a)^2=x^2+2ax+a^2=x^2-2kx+49
a^2=49
2ax=-2kx
a=+/- 7
a=-k
k=-a
k=+/- 7

Answer 4

perfect square
\[(a-b)^2=a^2-2ab+b^2\]
here
\[a=x\]
\[b^2=49\]
so
\[b=7\]

Answer 5

wait rsvitale, where do you get the a from?

Answer 6

k could be -7 too, (x+7)^2=x^2+14x+49, which would mean k=-7

Answer 7

a is just a variable for the second term in the binomial

Answer 8

why is it (a-b)^2
im confused about the beginning of the problem

Answer 9

thats the general form of a square of a binomial

Answer 10

so we want to see what the general form looks like expanded and find what k can be

Answer 11

\[(a+b)^2=(a+b)(a+b)=a^2+ab+ba+b^2=a^2+2ab+b^2\]

Answer 12

ok satelite, now explain from there. i get that step now so what do we do next... explain it like you just did.... sorry im not very good at math