What is the equation of the line that passes through the points (1, 2) and (3, 4)?
Correct: A
The equation of a line that passes through two points can be found by first finding the slope of the line and then using the point-slope form of a line. The slope of the line that passes through the points (1, 2) and (3, 4) is m = (y2 - y1)/(x2 - x1) = (4 - 2)/(3 - 1) = 2/2 = 1. The point-slope form of a line is y - y1 = m(x - x1). Plugging in the slope and the point (1, 2), we get y - 2 = 1(x - 1), which simplifies to y - 2 = x - 1, and then to y = x + 1.