ElectricPavlov

-4 x^2 -3x+2    is a dome shaped parabola        max will occur at x = -b/2a        b = -3   a = -4

   use this value of 'x' to calculate the max value

Put the biggest numbers in the  one's position:

9   +  * 8  + * * 7  +  *** 6         then put the next biggest numbers in the 10's place

9 + 58 + * 47 + **36                continue with the 100's place

9 + 58 + 247 + 0136               and then add them .....

20 pages/4 hr   *   x  hrs    +  20 pages/5hr  * x hr   = 900 pages

20/4  x      +  20/5  x   = 900      solve for 'x'  the number of hours

                                       then slower (typer) must type        20/5  * x   pages   .....

For it to have two real roots, the disciminant portion of the Quadratic Formula must = 0        (b²-4ac)=0

a = 8

b = 15  

c = c                   You should be able to take it from here......

1 .    a and b    =    -1/14 +- sqrt141 / 14    =    0.776739   and   −0.919596

             (via Quadratic Formula)

     so (a-4)(b-4) = 15.857

https://web2.0calc.com/questions/graphing-lines#r1

pi   is the ratio of the circumference to the diameter    circ/d = pi

(81^1/4)³ = 3³ = 27

This site is not a site to get your homework completed for you.....have you TRIED to answer any of these?

   Please post questions separately.....one question per post....   

sqrt(2018)+sqrt(2016 = 89.8220435317197012

sqrt(2019)+sqrt(2015) = 89.8220352522488239

sqrt(2020)+sqrt(2014) = 89.8220214531222153      Which is biggest ?