Question #103d5

3 Answers
Oct 19, 2016

Answer:

I got #50#

Explanation:

Consider the total as #x# (corresponding to #100%#); we can write that:
#x/9# must be the same as #(100%)/(18%)#
or:
#x/9=(100%)/(18%)#
rearranging:
#x=9*(100cancel(%))/(18cancel(%))=50#

Oct 19, 2016

Answer:

#50#

Explanation:

"Percent" literally means "per #100#". If we say something is #18%#, that is the same as writing #18/100#. When we say #18%# of a number, it is similar to how we might say #3# of a number. In the latter case, we would multiply by #3# to represent it algebraically. In this case, we multiply by #18% = 18/100#.

Let #x# represent our number. Writing our given information algebraically, then, we get

#18/100x = 9#

#=> 18/100x * 100/18 = 9*100/18#

(we multiply by the reciprocal of the coefficient of #x# to make #1# the new coefficient of #x#)

#:. x = 50#

Oct 19, 2016

Answer:

#18% xx 50 = 9#

Explanation:

You can work this out by writing an equation using #x# as the unknown number.

#18% " of what number is equal to " 9#?

#18/100 xx x = 9" "larr# now solve the equation for #x#

#x = 9 xx100/18#

#x = cancel9 xx100/cancel18^2#

#x = 50#