Difference of two squares will be
16y^2 -x^2 = (4y -x)(4y +x)
so the second choice
You would write it 2=10(20+2)
The answer is 90,000. Just remember 5 or above, give it a shove, and for or below let it go. Because 85 has a five at the end you push it up to 90. Same thing with 85,000 or 85,001. You shove it to 90. If it was 84,000 or 84,999 you would let it go to 80,000. Hope that helped!
Multiply 6 by each number in the matrix:
24, -12, 6
42, 18, 0
The 3rd answer is the correct one.