1872 + 1872
answers have to be more than 20 characters to post so um..
ELRIS COMEBACK 26/02
So, initially 240

-212

were empty:
this is :

12/4 is 4 so that's why i substituted it with 4.
now, later 27 1/3 were used so we add this tho the original empty space

=

=
which is the result!
A second degree polynomial function has the general form:

, where

.
The leading coefficient is a, so we have a=-1.
5 is a double root means that :
i) f(5)=0,
ii) the discriminant D is 0, where

.
Substituting x=5, we have
f(5)=a(5)^2+b(5)+c,
and since f(5)=0, and a is -1 we have:
0=-25+5b+c
thus c=25-5b.
By ii)

.
Substituting a with -1 and c with 25-5b we have:
Finally we find c: c=25-5b=25-50=-25
Thus the function is

Remark: It is also possible to solve the problem by considering the form

directly.
In general, if a quadratic function has leading coefficient a, and has a root r of multiplicity 2, then its form is
In order to solve, set up a proportion: 22/126=x/100. Cross multiply: 2200=126x. Divide by 126 on both sides: 17.46%=x
Most likely she incorrectly moved the decimal point in her calculation. The percent of a group cannot be more than 100.