Final answer:
To calculate the y-intercept of a linear equation, you need to know the slope and have one point on the line. Plug in the values into the equation y = mx + b and solve for b, which represents the y-intercept.
Step-by-step explanation:
In a linear equation of the form y = mx + b, the slope (m) represents the steepness of the line, while the y-intercept (b) represents the point where the line intersects the y-axis.
To calculate the y-intercept, you need to know the slope and have one point on the line. Once you have these values, you can use the formula: y = mx + b, where y is the y-coordinate of the known point, m is the slope, x is the x-coordinate of the known point, and b is the y-intercept you're trying to find.
For example, if the slope is 2 and a point on the line is (3, 5), you can substitute these values into the equation: 5 = 2(3) + b. Simplifying this equation, you get: 5 = 6 + b. By subtracting 6 from both sides, you find: b = -1. So the y-intercept of this line is -1.