Supposing the two is supposed to be a squared:
Multiply (FOIL) it out: (4y-3)(4y-3)
16y²-12y-12y+9 = 16y²-24y+9=72
Subtract 72 from both sides: 16y²-24y-63=0
Use quadratic formula (let me know if you want me to type it out), or just use your calculator: x should turn out to be 2.871 or -1.371