This equation is in slope-intercept form, which is y = mx + b, where m is the slope and b is the y-intercept.
Note that parallel lines have the same slope.
The equation is y = 2x - 1; the slope is 2 and the y-intercept is (0, -1).
For our line parallel to the given line, we have y = 2x + b, as the slopes are the same. To find b (the y-intercept), plug the point on the line - (4, 2) - for x and y in the equation and solve algebraically for b.
y = 2x + b
2 = 2(4) + b
2 = 8 + b
-6 = b
We can now complete our equation!
y = 2x - 6
However, notice how the options aren't in slope-intercept form. Simply isolate and negate the constant to figure out which one is correct.
y = 2x - 6
y - 2x = -6
-y + 2x = 6
2x - y = 6
Answer:
The equation of the line that passes through (4, 2) and is parallel to the line y = 2x - 1 is B) 2x - y = 6.