that is where the line crosses the x axis or where y=0
0=-16x^2+22x+3
we gon do grouping
ac method
-16 times 3=-48
what 2 numbers multiply to get -48 and add to get 22
-2 and 24
0=-16x^2-2x+24x+3
group
0=(-16x^2-2x)+(24x+3)
undistribute
0=-2x(8x+1)+3(8x+1)
undistribute
0=(8x+1)(-2x+3)
set eaqual to 0
8x+1=0
8x=-1
x=-1/8
-2x+3=0
3=2x
3/2=x
x intercepts ate x=-1/8 and x=3/2