Answer:
Step-by-step explanation:
If J can paint a room in 3 hours, in 1 hour she gets of the job done.
If A can paint a room in 4 hours, in 1 hour she gets of the job done. We need to find out how long it takes them if they paint together. The equation for this is:
where x is the number of hours it takes them to get the job done together. Multiply everything through by 12x to get
4x + 3x = 12 so
7x = 12 and
x = 1.7 hours to get the room painted together.
For this case we must indicate which of the equations shown can be solved using the quadratic formula.
By definition, the quadratic formula is applied to equations of the second degree, of the form:
Option A:
Rewriting we have:
This equation can be solved using the quadratic formula
Option B:
Rewriting we have:
It can not be solved with the quadratic formula.
Option C:
Rewriting we have:
This equation can be solved using the quadratic formula
Option D:
Rewriting we have:
It can not be solved with the quadratic formula.
Answer:
A and C