Answer: Option A
or 
Step-by-step explanation:
Use the quadratic formula to find the zeros of the function.
For a function of the form
The quadratic formula is:
In this case the function is:
So
Then using the quadratic formula we have that:
Remember that 
or
the height of the poster must be multiplied by the ratio which is 1 to 2.5 which is 40 cm.
It introduces the relationship between two variables and is called correlation. Proportionality or variation is state of relationship or correlation between two variables It has two types: direct variation or proportion which states both variables are positively correlation. It is when both the variables increase or decrease together. On the contrary, indirect variation or proportion indicates negative relationship or correlation. Elaborately, the opposite of what happens to direct variation. One increases with the other variables, you got it, decreases. This correlations are important to consider because you can determine and identify how two variables relates with one another. Notice x = y (direct), y=1/x (indirect)
