Can someone please help me? I’m stuck and don’t understand.

I guess you are stuck with 7., because I don't see any notes there.

square both sides

the root and the square cancel each other

2c + 3 = 25

subtract 3 on both sides

2c = 22

devide by two on both sides

c = 11

a) 4 -4x + 1 = 0     (standard form. Just subtract 3 from both sides)

b) Vertex (,0)

c) c = 11

Step-by-step explanation:

You got the line of symmetry correct.

Vertex looks good.

c) square both sides. solve for c.

step-by-step explanation:

you can add the two numbers and divide the result by 2. or you can find the gap between the two numbers and add half of this to the smaller number.