9514 1404 393
Answer:
y = x² +4x -21
Explanation:
In standard form with a leading coefficient of 1, you have ...
y = x² +bx +c
The coefficient 'b' is the opposite of the sum of the roots: -(3 +(-7)) = 4.
The constant 'c' is the product of the roots: (3)(-7) = -21.
So, the equation is ...
y = x² +4x -21