Find Slope and Starting Value

5 questions0m 0s

Learn the skill

For a line, slope is change in y divided by change in x. In y = mx + b, m is slope and b is y when x is zero. Use a known point to check your rule.

Worked example

A line through (1, 5) and (3, 11) has slope (11 - 5)/(3 - 1) = 3. Substituting the first point gives 5 = 3 + b, so b = 2 and y = 3x + 2.

1. A line passes through (0, 4) and (2, 10). What is its slope? Answer

2. In y = 5x - 7, what is the y-intercept? Answer

3. For y = -2x + 9, what is y when x = 4? Answer

4. A line has slope 4 and passes through (2, 11). What is b in y = 4x + b? Answer

5. A straight-line table gives (1, 8), (3, 14), and (5, 20). What is y when x = 0? Answer