Hello!
To find the x-intercept given the equation of a line, we substitute y for 0 and solve for x.
0=4x²-9
We add 9 to both sides.
9=4x²
We find the square root of both sides.
3=4x
We divide both sides by 4.
x=3/4
Therefore, our x-intercept is 3/4.
I hope this helps!