Question #8d374

Question

1238 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-08-22T12:49:41

See a solution process below:

Because we are not allowed to divide by #0# the excluded values for the expression: #(5x + 15)/(x^2 - 49)# are #x^2 - 49 != 0#

To find the values of #x# where this exclusion is true we need to solve the denominator for #0#:

#x^2 - 49 = 0#

#x^2 - 49 + color(red)(49) = 0 + color(red)(49)#

#x^2 - 0 = 49#

#x^2 = 49#

#sqrt(x^2) = +-sqrt(49)#

#x = +-7#

The excluded values are: #x != -7# and #x != 7#