Answer
0.05x$^3$+0.02x$^2$+1.02x
Work Step by Step
Distribute the negative to the parentheses and then combine like terms vertically.
$\quad0.07x^3-0.01x^2+0.02x$
$\underline{-(0.02x^3-0.03x^2-\quad x)}$
$\qquad\qquad\quad\downarrow$
$\quad0.07x^3-0.01x^2+0.02x$
$\underline{-\;0.02x^3+0.03x^2+\quad x}$
$\quad0.05x^3+0.02x^2+1.02x$