Question #36b7c

1 Answer
Dec 5, 2017

The number, #x#, is equal to #-2#.

Explanation:

Let’s break it down.

“Three times the sum of five times a number . . .”

So we’re multiplying #3# by #5# multiplied by a number, which we’ll call #x\implies3(5x)#

“ . . . and #4#

#5x# is being added to #4#, which we can represent as #3(5x+4)#.

“ . . . is #-18#.”

That means the above expression equals #-18#:

#3(5x+4)=-18#

Now simply solve for #x# by distributing the #3#:

#\implies 15x+12=-18#

Subtracting #12# from both sides:

#\implies 15x=-30#

Divide both sides by #15#:

#x=-2#