Answer:
1.25 cups
Step-by-step explanation:
The inicial concentration of the 10 cups of mixture is 10% of white vinegar and 90% water. We can then calculate the number of cups of white vinegar in the mixture:
Amount of white vinegar = 10% of 10 cups = 1 cup of white vinegar
Concentration of white vinegar = 1/10 (cups of white vinegar over cups of mixture
So, if we want to add white vinegar (x cups) until the mixture will be 20% white vinegar and 80% water, we have that:
Amount of white vinegar = (1+x) cups of white vinegar
Total number of cups in the mixture = 10+x
Concentration of white vinegar = 20% = (1+x)/(10+x)
(1+x)/(10+x) = 0.2
1 + x = 2 + 0.2x
0.8x = 1
x = 1.25 cups
You need to add 1.25 cups of white vinegar.
<u>Answer:</u>
○ 
<u>Explanation:</u>
<h3>What is a quadratic equation?</h3>
A quadratic equation is an algebraic equation where the highest power of 
is 2. The general form of a quadratic equation is as follows:
,
where <em>a</em>, <em>b</em>, and <em>c</em> represent known constants, and is the unknown.
In this question, if you take a look at the second option, you will see that it is possible to rearrange the equation to make it look the general form:
⇒ 
Therefore, this equation is quadratic.
The other three options are not quadratic equations because none of them have an 
term in them.
149x62=9238
268x3)=no answer syntax error
340x25=8500
463x81=37503
524
