Whenever a quadratic equation is in the form
(i.e. the leading terms is 1), you can solve it by looking for two numbers that give 
when summed and 
when multiplied.
So, in your case,
So, we're looking for two numbers 
such that:
you can clearly check that these numbers are 3 and 4.
To solve this problem, let us first assign variables. Let
us say that:
x = volume of 67% herbicide solution
y = volume of 46% herbicide solution
The total volume should be 42 liters therefore:
x + y = 42
x = 42 – y --> 1
The component mass balance on the pure herbicide would
be:
0.67 x + 0.46 y = 0.55 (42) --> 2
Substituting equation 1 to 2:
0.67 (42 – y) + 0.46 y = 23.1
28.14 – 0.67 y + 0.46 y = 23.1
- 0.21 y = - 5.04
y = 24 L
Calculating for x using equation 1:
x = 42 – 24
x = 18 L
Therefore we only need 18 L of the 67% herbicide
solution.
Answer:
A. 18 L
Answer:
He goes 4 miles
Step-by-step explanation:
