This is a way to factoring trinomials (there exist different equivalent methods).
Multiply the trinomial but the term accompanying . This is the second line. Then, you could take the square of the 
, ant try to create a factor () () that will correspond to the expression in the second line. That is, we want 
In ? we put the corresponding numbers that, if we multiply them we will obtain 42, and if we add them we will obtain 13. This numbers are 6 and 7. Then, we have 
The last step is divide by the number that we multipy in the first step.
Answer:
Step-by-step explanation: 60 ÷ 0.25 = 240
240 is your selling price
The answer is 12.8 cm³
<span>The volume ( v) of a gas in a container at a constant temperature varies inversely as the pressure (p):
v = k/p
p * v = k (k - constant)
p1v1 = k
p2v2 = k
So, p1v1 = p2v2
v1 = 24 cm</span>³
p1 = 16 lb
v2 = ?
p2 = 30 lb
24 * 16 = x * 30
384 = x * 30
x = 384 / 30
x = 12.8 cm³
Because it is normally set to only find real roots, not complex roots
if you are smart, you can use the factor function and use your head to find those roots
