1. How many pupils are there in my class ? 2. What are there ? 3. Where are you ? 4. Where do you live ? Chúc bạn học tốt

16x (4x²-5) + 17 = (4x + 1) (16x²-4x + 1)
64x³-80x + 17 = 64x³ + 1
64x³-64x³ = 1-17-80x
-80x = -16
x = -16 / ( -80)
x = 0,2