Answer:
7
Step-by-step explanation:
8x-2y=48, replace y with 4, 8x-2(4)=48, multiply, 8x-8=48, add 8 to both sides to remove the -8, 8x=56 and finally divide by 8 to remove 8 from x, x=7.
sqrt (-1) = i the imaginary number
so the negative sqrt (-1) = -i