Answer:
x=2 or x=-2
Explanation:
ax^2+bx+c=0
first we rearrange this equation so we get x^2+(-4+4)x-4=0 so its x^2-4=0 so that means b=0 now we should find two numbers that when we multiply them we get c and when we subtract them we get b so that two numbers are 2 and -2