standard_description: Use similar triangles to explain why the slope m is the same between any two distinct points on a non-vertical line in the coordinate plane; derive the equation y = mx for a line through the origin and the equation y = mx + b for a line intercepting the vertical axis at b.
problem_activity: Task
Use <, =,  or > to compare the following sums:
$\frac12 + \frac14$  ________  $\frac13 + \frac15$
$\frac13 + \frac12$  ________  $\frac13 + \frac14$


aligns: no