Then/Now You wrote linear equations given either one point and the slope or two points. (Lesson...

You wrote linear equations given either one point and the slope or two points. (Lesson 4–2)

• Write equations of lines in point-slope form.

• Write linear equations in different forms.

• point-slope form

Write and Graph an Equation in Point-Slope Form

Point-slope form

Write the point-slope form of an equation for a line

that passes through (–2, 0) with slope

Write and Graph an Equation in Point-Slope Form

Answer:

Graph the equation

Plot the point at (–2, 0).

Use the slope to find another point on the line. Draw a line through the two points.

A. A

B. B

C. C

D. D A B C D

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Write the point-slope form of an equation for a line that passes through (4, –3) with slope –2.

In standard form, the variables are on the left side of the equation. A, B, and C are all integers.

Writing an Equation in Standard Form

A. A

B. B

C. C

D. D A B C D

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Write y – 3 = 2(x + 4) in standard form.

Writing an Equation in Slope-Intercept Form

A. A

B. B

C. C

D. D A B C D

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Write 3x + 2y = 6 in slope-intercept form.

Point-Slope Form and Standard Form

A. GEOMETRY The figure shows trapezoid ABCD with bases AB and CD.

Write an equation in point-slope form for the line containing the side BC.

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Point-Slope Form and Standard Form

Step 1 Find the slope of BC.

Slope formula

(x1, y1) = (4, 3)

(x2, y2) = (6, –2)

Point-Slope Form and Standard Form

Step 2 You can use either point for (x1, y1) in the point-slope form.

Using (4, 3) Using (6, –2)

y – y1 = m(x – x1) y – y1 = m(x – x1)

Point-Slope Form and Standard Form

B. Write an equation in standard form for the same line.

A. A

B. B

C. C

D. D A B C D

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A. The figure shows right triangle ABC. Write the point-slope form of the line containing the hypotenuse AB.

A. A

B. B

C. C

D. D A B C D

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B. The figure shows right triangle ABC. Write the equation in standard form of the line containing the hypotenuse.