Final answer:
The equation of a line with a given slope and y-intercept, as well as the equation of a line passing through a given point with a given slope, can be determined using specific formulas.
Step-by-step explanation:
The equation of a line in slope-intercept form is given by y = mx + b, where m is the slope and b is the y-intercept.
For the first question, since the slope is 3 and the y-intercept is 4, the equation of the line is y = 3x + 4.
For the second question, we can use the point-slope form of the equation. The equation can be written as y - y1 = m(x - x1), where (x1, y1) is the given point and m is the slope. Plugging in the values (1,5) and 3 for the slope, we get y - 5 = 3(x - 1), which simplifies to y - 5 = 3x - 3. Rearranging the equation, we have y = 3x + 2 as the equation of the line.