Quadratics: Writing Vertex Form, Algebra 1- Mrs. Daniel, Kuta Software

vertex form is given by:
y=a(x-h)^2+k
where the vertex is (h,k)
7. (h,k)=(-4,1)
plugging in the equation we get:
y=a(x+4)^2+1
but substituting (0,2) in the equation and solving for a we get:
2=a(0+4)^2+1
a=1/16
hence:
Answer: y=1/16(x+4)^2+1

8] 
(h,k)=(2,-4)
thus
y=a(x-2)^2-4
plugging point (3,0) in the eqn and solving for a we get
0=a(3-2)^2-4
0=a-4
a=4
hence;
Answer: y=a(x-2)^2-4

9] (h,k)=(3,3)
thus;
y=a(x-3)^2+3
plugging (2,2) in the equation we get:
2=a(-1)^2+3
a=-1
thus;
Answer: y=-1(x-3)^2+3

10] (h,k)=(-1,-1)
y=a(x+1)^2-1
plugging (0,-3) in the equation and solving for a we get:
-3=a(1)^2-1
a=-2
thus
Answer: y=-2(x+1)^2-1

11] (h,k)=(1,2)
y=a(x-1)^2+2
plugging (0,4) in the equation and solving for a we get:
4=a(-1)^2+2
a=2
thus
y=2(x-1)^2+2

12] (h,k)=(3,-2)
y=a(x-3)^2-2
plugging (2,0) and solving for a we get:
0=a(2-3)^2-2
a=2
thus
t=2(x-3)^2-2