Hey there!
Here is your answer:
The proper answer to this question is "40".
Reason:
40/x=100/45
(40/x)*x=(100/45)*x - we multiply both sides of the equation by x
40=2.22222222222*x - we divide both sides of the equation by (2.22222222222) to get x
40/2.22222222222=x
18=x
x=18
45% of 40=18
If you need anymore help feel free to ask me!
Hope this helps!
~Nonportrit