Question #c7dcd

1 Answer
Jan 20, 2018

x=6

Explanation:

Move the 80 over.
#-(8-x)(10-x) = -8#

FOIL or whatever you do,
#-(80-18x+x^2) = -8#

-1 to both sides
#x^2-18x+80=8#

Move the 8 over.
#x^2-18x+72=0#

Factor
#(x-12)(x-6)=0#

The answer is #x=6 and 10#
#x=6 because 10# as x is unfeasible