Forms of Linear Equations

Linear Equations & FunctionsPage 1 of 2

Slope-Intercept Form: The slope intercept form of an equation of a line is y = mx + b.The slope is m and y-intercept is b.

y-intercept: The point where the graph crosses the y-axis.

Point-Slope Form: If the point with coordinates (x1, y1) lies on a line having slope m, the point-slope form of the equation of the line can be written as follows:y - y1= m(x - x1)

#1) (-6, 4), 8

Slope-intercept form:

#2) (-12, 5),

Slope-intercept form:

#1) (-1, 6), (-1, 11)

Point-slope form:

Slope-intercept form:

#2) (1, -5), (3, -1)

Point-slope form:

Slope-intercept form:

Note:Write down the point slope form. Sub in for (x1, y1) and m. Change equation till it is in correct form.

Note:You first need to find the slope using the slope formula.

Write down the point slope form. Sub in for (x1, y1) and m. Change equation till it is in correct form.

Notes # Alpha 5

Ex A: Write the slope-intercept form of the equation of the line through the point with the given coordinates and having the given slope.

Ex B: Write the point-slope form of the equation of the line through the points with the given coordinates. Then write the equation is slope-intercept form.

Forms of Linear Equations

Linear Equations & FunctionsPage 2 of 2

#1) f(x) = mx - 4

#2) f(x) = mx + 5

#1) In 1984, medical expresses were 10.3% of the gross national product (GNP) and in 1987, medical expenses were 10.9% of the GNP. Assuming that the growth continues at that rate, write a linear equation in slope-intercept form to describe the percent of gross national product devoted to medical expenses, y, in year x.

#2) The Fluff Detergent Company manufactures detergent with a fixed overhead cost of $5000. In addition, each box of Fluff Detergent costs $0.40 to produce. Write an equation that represents the total cost, C(x), of producing x boxes of Fluff. Then find the fixed cost and the variable cost per box of Fluff.

Ex C: Use a graphing calculator to graph each function, without erasing, for m = 1, m = -3, and m = 5. Explain how the graphs are alike and different.

Ex D: Complete the following word problems.

Note: When making equations make sure x is the independent variable and y is the dependant variable.

Note: When making equations make sure x is the independent variable and y is the dependant variable.