If u = x³ - 10 is substituted into ∫x²(x³ - 10)dx, then we have ∫u¹/² x² dx = u¹/²∫x² dx. We must also convert ∫x² dx into an expression involving u.

a) u³/²- 30u¹/²
b) u¹/² - 30u³/²
c) u³/² + 30u¹/²
d) u¹/² + 30u³/²