Two friends wash cars to make extra money. The profit P(x) of one friend after x days can be represented by the function P(x) = −x2 + 9x + 10. The second friend's profit can be determined by the function Q(x) = 12x. Solve the system of equations. What solution is a viable answer to the question, "After how many days will the two students earn the same profit?" and which solution is a nonviable answer? Show your work and justify your answer.

Question

yoselinr2006 · Answer

i really need help on itttt

jhonyy9 · Answer

can you solve a system of equations ?

yoselinr2006 · Answer

I'm not really good at it i don't fully understand it.. so I'm having trouble trying to answer this one

yoselinr2006 · Answer

I do flvs..and my algebra2 grade is a d... and i need to do a discussion assignment on the question..and I need help

jhonyy9 · Answer

$$-x^{2} + 9x +10 = 0$$

$$12x = 0$$

this is your system

yoselinr2006 · Answer

okk

yoselinr2006 · Answer

how do i explain the strategy tho

yoselinr2006 · Answer

because i have to explain how i gotthat answer...and the answer i put before was from the intertnet.. i used the wrong equation

jhonyy9 · Answer

ok I will try explain to you - hope understandably

12x = 0

how you calcule the x value from this equation ?

yoselinr2006 · Answer

you find a number to substitute 0 and then divide them ??

jhonyy9 · Answer

divide both sides by 12 so in this way what value will get for x ?

yoselinr2006 · Answer

you would be left with just x

yoselinr2006 · Answer

so 0?

jhonyy9 · Answer

yes of cours x = 0

yoselinr2006 · Answer

okk so thats rigt

jhonyy9 · Answer

ok remember on this please

so now the first equation is a quadratic function - yes ?

yoselinr2006 · Answer

yes

jhonyy9 · Answer

ok what is the diagram of a quadratic function ?

jhonyy9 · Answer

is a parabola

jhonyy9 · Answer

two equations when has common roots ?

yoselinr2006 · Answer

its a quadratic function..

jhonyy9 · Answer

when their diagrams intersects

and the intersection point is the common root

when two equations havent common roots so from this result that their diagram dont intersect never

yoselinr2006 · Answer

ohh

yoselinr2006 · Answer

okk

jhonyy9 · Answer

in this case for second equation you get x = 0
and hope you know that this equation has a diagram what intersect the origin

yes ?

yoselinr2006 · Answer

yes

jhonyy9 · Answer

so now then you substitute the x=0 in place of x inside the first equation so what will get ?
the left side value will be equal with right side value of 0 ?

jhonyy9 · Answer

please try it

yoselinr2006 · Answer

12?..im sorryy

jhonyy9 · Answer

no

for P(0) = ?
what will get ?

yoselinr2006 · Answer

and if not than i think 1

jhonyy9 · Answer

@jhonyy9 wrote:

$$-x^{2} + 9x +10 = 0$$ $$12x = 0$$ this is your system

here in place of x substitute 0 p(0) = ?

yoselinr2006 · Answer

i think its something divided by 12 a numbe greatrer than 1 ofc..maybee 6

yoselinr2006 · Answer

im not sure

jhonyy9 · Answer

$$P(0)= -0^{2} +9×0 +10$$

so P(0) = ?

yoselinr2006 · Answer

19 to the power 0f 2 ?can that give me the answer

yoselinr2006 · Answer

if 9 times 0 is 0 then its just 9 + 10

yoselinr2006 · Answer

9+10 - 0^2

jhonyy9 · Answer

no

the first term there is - zero on power of two = ?

yoselinr2006 · Answer

attachment

jhonyy9 · Answer

@jhonyy9 wrote:

$$P(0)= -0^{2} +9×0 +10$$ so P(0) = ?

here the first term -0 on power of 2 = 0 yes ? the second term how you said is correct so 9×0 = 0 and now there are 0 + 0 +10 = ?

yoselinr2006 · Answer

jus 10

jhonyy9 · Answer

from this result

P(0) = 10

and you remember the second equation was

Q(0) = 0

yes ?

yoselinr2006 · Answer

right

jhonyy9 · Answer

so for the same x = 0 these equations give different results

from this result that these equations havent common roots so what mean that their diagram dont intersect never

what result from this like answer on your posted problem ?

yoselinr2006 · Answer

wha do you mean

jhonyy9 · Answer

@xxdeppressionxx

yoselinr2006 · Answer

so the answer is x=0

yoselinr2006 · Answer

and the equations do not intetrsect

jhonyy9 · Answer

no the answer not is x= 0 bc. this is a root just for second equation 
but from this result that these equations havent common roots so dont will intersect never

and what mean this for these two friends ? can they have the same profit ?

yoselinr2006 · Answer

no

yoselinr2006 · Answer

because they have no common root

jhonyy9 · Answer

because these two equations havent common roots so this mean that these two friends not can have the same profit never

jhonyy9 · Answer

Idk do you understand my help ?

yoselinr2006 · Answer

yes, just a Lil...but thank you so much for your time I appreciate it.

jhonyy9 · Answer

ok np anytime

cya

WickedHeart · Answer

@yoselinr2006

If this is done please close