Plz me with these 2 problems i really need it and i need to know how you to the answer so i can show my work

13.) 0.19625    15.) 37.68

Step-by-step explanation:

Formula for area of a circle: A=πr²

13.) 3.14 x .25² = 0.19625

Formula for circumference for a circle: C=πD  or C=2πr

15.) (6 x 2) x 3.14 = 37.68

Hope this helped :  )

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.