Answer:
22.360679775 in
Step-by-step explanation:
a squared plus b squared = c squared
10 x 10 = 100
20 x 20 = 400
500 = c squared
22.360679775 = c
y = -4(x+6)(x-8)
= -4[x²-2x-48]
= -4x²+8x+192