Combine like terms to write the expression in standard form (−r +s) + (s − r)

First we clear brackets

 -r+s+s-r

Second we collect like terms

-r-r+s+s

then we add it

-2r +2s

if we read the question it says standard form so we out the G.C.F of the

expression

2(-r+s)

coins of silver or gold

step-by-step explanation:

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.