slope vocabulary & steps to solve certain situations

### slope

the steepness of a line on a graph, equal to its vertical change divided by its horizontal change; rise over run; rate of change

### direct variation

an equation of the form y = kx, where k is not equal to 0; "y varies directly with x"; k = y/x

### Write an equation of a line given two points (x1, y1) & (x2, y2)

Step 1: Find slope

Step 2: Use one point and the slope and plug in point-slope form

Step 3: Solve for y to get it in slope-intercept form

### Standard Form

Ax + By=C, where A, B, and C are not decimals or fractions, where A and B are not both zero, and where A is not a negative