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: Problem 1
Solve the equation below. For each step, explain why each line of your work is equivalent to the line before it.
$${\frac{1}{2}(-12x+4)+5x=\frac{2}{3}(24)}$$
Problem 2
Find and explain the error in the work below.
$${15=-3(m-2)-9}$$
$${15=-3m+6-9}$$
$${15=-3m-3}$$
$${12=-3m}$$
$${m=-4}$$


aligns: no