For #3
A quadratic expression is in standard from when written as ax^2 + bx + c = 0. Where, a, b, and c are constants.
The only option that is written in the form above is option C. Where a=-1, b=-5, and c=7.
For #4
First how is 3x^2 in standard form?
Recall that the standard form of a quadratic is ax^2 + bx + c = 0. So lets alter 3x^2 a bit to show that it is in standard form.
3x^2 ==> 3x^2+0x+0
As you can see 3x^2 is in standard form, but the constants b and c are zero.
Second, how is 3x^2 in factored form?
Factored form is written as (a+x)(b+x). So let's alter 3x^2.
3x^2 ==> 3(0+x)(0+x)
3(0+x)(0+x) = 3(x)(x) which is 3x^2
Hence it can be said that 3x^2 is in both standard and factored form.