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Find any points of discontinuity for the rational function. What are the points of discontinuity? Are they all removable?

y = (x-7)(x-3) / x^2-10x+21

Ax = 1, x = –8, x = –2; yes
Bx = 7, x = 3; yes
Cx = –7, x = –3; no
Dx = –1, x = 8, x = 2; no

Verified Answer :

factor
\(\frac{(x-7)(x-3)}{(x-7)(x-3)} =1\)
it simplifies to y=1
(x-7)(x-3)
they are undefined since they make the denomenator 0
solve
(x-7)(x-3)=0
x-7=0
x=7
x-3=0
x=3
restricted values are x=3 and x=7
but, the points x=3 and x=7 are holes since they were canceled out

answer is B

The answer would be B.