Question 37236
Create the quadratic equation in the form ax squared + bx + c using the point 
(-1,7) as one point and the point (10,-8) as the vertex. enter a,b,c values as common fractions in reduced form. 

Because the vertex is (10,-8),
-b/2a=10
Then b=-20a
Rewrite the equation as follows:
y=ax^2-20ax+c
Using the point (-1,7) you get:
7=a+20a+c
Using the point (10,-8) you get:
-8=100a-200a+c
Rewriting both of these you get two equations in a and c, as follows:
7=21a+c
-8=-100+c
Subtracting the 1st from the 2nd you get:
15=121a or a=15/121
Substituting that back you can solve for c which is c=532/121
Substituting back into y=ax^2-20ax+c you get the equation you want:
y=(15/121)x^2-(300/121)x+(532/121)
Cheers,
Stan H.