Page 145 - Math Course 3 (Book 1)

Equations in Different Forms

Write an Equation in Point-Slope Form

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

A. y – 6 = 1(x – 4) A. –x + y = 10
B. y – 1 = 1(x – 3) B. –x + y = 3
C. y + 4 = 1(x + 6) C. –x + y = –2
D. y – 4 = 1(x – 6) D. x – y = 2

Answer Answer

MO. 4 - L5b
Linear Equations in Let’s Begin

Different Forms

Concept Summary Write an Equation of a Horizontal Line

Writing Equations Example

Given the Slope and One Point
Step 1 Write the point-slope form of an equation for a
Substitute the values of m, x and y into the slope- horizontal line that passes through (0, 5).
interception form and solve for b. Or use the point
-point form. Substitute the value of m and let x
and y be (x – x )
1 1
Step 2
Write the slope-interception form using the values
of m and b.

Given Two Points
Step 1
Find the slope.
y – y = m(x – x ) Point-slope form
Step 2 1 1 (x , x ) = (0, 5)
Choose one of the two points to use. y – 5 = 0 (x – 0) 1 1
y – 5 = 0 Simplify.
Step 3
Follow the steps for writing an equation given the
slope and one point.
Answer The equation is y – 5 = 0.

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