I don't know but these can be really difficult
good luck
5x^3+8x^2/3x^4-16x^2=x^2(5x+8)/x^2(3x^2-16)=5x+8/3x^2-16
lim x--->0 5x+8/3x^2-16=8/-16=-1/2
4x - 2 = 2x + 8
2x -2 = 8
2x = 10
x = 5
4(5)-2 = 2(5)+8
20-2 = 10+8
18 = 18
3 is multiplying by itself 7 times. The answer is 3 superscript 7.