Question

Rule for x intercepts at (4,0) and (-1,0) and opening upward

Answer 1

This is a quadratic equation:
y = a x² + b x + c,  a > 0 ( opening upward )
The zeroes are: ( - 1 , 0 ) and ( 4, 0 ). 
y = a ( x - x 1 ) ( x - x 2 )
y = a ( x + 1 ) ( x - 4 )
y = a ( x² - 4 x + x - 4 )
y = a ( x² - 3 x - 4 )