The minutes remaining till the end of the month = 500 - 310 = 190 minutes
now to split these minutes equally, we will divide them by 7 days of week
daily usage = 190/7 = 27.14 minutes
since we can not talk for 0.14 minutes, therefore,to equally split the remaining minutes, you should speak 27 minutes per day with one extra minutes remaining to be used on the day you choose
Answer:
y=1/4x+5
Step-by-step explanation:
\left[x \right] = \left[ \frac{5\,y}{158}+\frac{6\,z}{79}\right][x]=[1585y+796z] totally answer
B - 7x = a - b
Subtract b from both sides.
-7x = a - 2b
Divide both sides by -7.
x = 
![y=x^5-3\\ y'=5x^4\\\\ 5x^4=0\\ x=0\\ 0\in [-2,1]\\\\ y''=20x^3\\\\ y''(0)=20\cdot0^3=0](https://tex.z-dn.net/?f=y%3Dx%5E5-3%5C%5C%20y%27%3D5x%5E4%5C%5C%5C%5C%205x%5E4%3D0%5C%5C%20x%3D0%5C%5C%200%5Cin%20%5B-2%2C1%5D%5C%5C%5C%5C%20y%27%27%3D20x%5E3%5C%5C%5C%5C%0Ay%27%27%280%29%3D20%5Ccdot0%5E3%3D0)
The value of the second derivative for
is neither positive nor negative, so you can't tell whether this point is a minimum or a maximum. You need to check the values of the first derivative around the point.
But the value of
is always positive for
. That means at
there's neither minimum nor maximum.
The maximum must be then at either of the endpoints of the interval
![[-2,1]](https://tex.z-dn.net/?f=%5B-2%2C1%5D)
.
The function
is increasing in its entire domain, so the maximum value is at the right endpoint of the interval.
