How do you simplify #3.5x-7.5x#?

1 Answer
Aug 11, 2016

Probably I confused things a bit!

Explanation:

You could simply subtract the numbers because the two terms are similar (they contain the #x# both of them) so you can subtract them simply operating on the numbers maintaining the #x# as it is; but I thought of a more interesting approach.

Let us write your operation as:
#35/10x-75/10x=# (which is the same thing)
take the common denominator #10# and write:
#=(35x-75x)/10=#
now subtract the numerators:
#=(-40x)/10=#
divide by #10#:
#=-4x#