#### Answer

$y=\frac{1}{2}x$.

#### Work Step by Step

RECALL:
(i) The slope-intercept form of a line's equation is $y=mx+b$, where m=slope and b=y-intercept.
(ii) The line passes through the y-axis at the point (0, b).
The given line has $m=\frac{1}{2}$, therefore its tentative equation is $y=\frac{1}{2}x+b$.
The y-intercept is (0, 0) therefore $b=0$.
Thus, the equation of the line is $y=\frac{1}{2}x$.