6
Step-by-step explanation:
Step 1:
Let Rachel scored 33 points in total
Let a be the 1 point and b be the 2 point.
a = 21 points scored by 1 point. We want to find b
Step 2:
a+b=33
b= 33-a
= 33-21
= 12
b=12 points which means 6 double points
if we zero out f(x), namely make y = 0, we can get the roots or x-intercepts for this quadratic equation

now, the equation is in x-terms, meaning is a vertically opening parabola, so the axis of symmetry will be x = something, a vertical line.
well, we have two x-intercepts, one at -4 and another at 2, and the vertex is right half-way between those guys
-4------------(-1)------------2
so the vertex is at x=-1, namely the axis of symmetry is x = -1.
4x+7=35
4x=28
x=7
A corresponding solution of the matching equation is a fancier way of telling you to find the number that represents x
In order to add these fractions we have to make a common denominator.
1/5 can turn into 2/10 Its the same thing. And its easier to solve with.
now lets multiply.
× 
Now we add across
2 + 1 = 3
------------
10 + 10 = 10 ( When adding fractions like these the denominator stays the same)
So your answer is...

Good Luck! :)