Hi, I have some problems with approximation.I'll be glad if you could help.We just learnt basics.I can't solve this kind of questions.

App.(2.9)³

2x^4 + 5x³ - 7x ^2 +8x -3 X= 1.03

How accurately must the edge of a cube be measured so that the volume will be correct to within 3% ?

Thanks in advance. I have an exam on Saturday ! Your help will be much appreciated.