Respuesta :
if we take 80 to be the 100%, what is 30% off of that anyway?
[tex]\bf \begin{array}{ccll} amount&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 80&100\\ x&30 \end{array}\implies \cfrac{80}{x}=\cfrac{100}{30}\implies \cfrac{80\cdot 30}{100}=x[/tex]
so the markup amount is "x".
[tex]\bf \begin{array}{ccll} amount&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 80&100\\ x&30 \end{array}\implies \cfrac{80}{x}=\cfrac{100}{30}\implies \cfrac{80\cdot 30}{100}=x[/tex]
so the markup amount is "x".
1. We assume, that the number 80 is 100% - because it's the output value of the task.
2. We assume, that x is the value we are looking for.
3. If 80 is 100%, so we can write it down as 80=100%.
4. We know, that x is 30% of the output value, so we can write it down as x=30%.
5. Now we have two simple equations:
1) 80=100%
2) x=30%
where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that:
80/x=100%/30%
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.
7. Solution for what is 30% of 80
80/x=100/30
(80/x)*x=(100/30)*x - we multiply both sides of the equation by x
80=3.33333333333*x - we divide both sides of the equation by (3.33333333333) to get x
80/3.33333333333=x
24=x
x=24
now we have:
30% of 80=24