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Determine the gradient of the straight line 2x-3y+9=0. Find the equation of the straight line through the origin which is perpendicular to the line 2x-3y+9=0.

User Hsu
by
2.3k points

2 Answers

8 votes
8 votes

Answer: 3

x

2

y

15

=

0

Explanation:

We know that,

the slope of the line

a

x

+

b

y

+

c

=

0

is

m

=

a

b

The slope of the line

2

x

+

3

y

=

9

is

m

1

=

2

3

The slope of the line perpendicular to

2

x

+

3

y

=

9

is

m

2

=

1

m

1

=

1

2

3

=

3

2

.

Hence,the equn.of line passing through

(

3

,

3

)

and

m

2

=

3

2

is

y

(

3

)

=

3

2

(

x

3

)

y

+

3

=

3

2

(

x

3

)

2

y

+

6

=

3

x

9

3

x

2

y

15

=

0

Note:

The equn.of line passing through

A

(

x

1

,

y

1

)

and

with slope

m

is

y

y

1

=

m

(

x

x

1

)3

x

2

y

15

=

0

Explanation:

We know that,

the slope of the line

a

x

+

b

y

+

c

=

0

is

m

=

a

b

The slope of the line

2

x

+

3

y

=

9

is

m

1

=

2

3

The slope of the line perpendicular to

2

x

+

3

y

=

9

is

m

2

=

1

m

1

=

1

2

3

=

3

2

.

Hence,the equn.of line passing through

(

3

,

3

)

and

m

2

=

3

2

is

y

(

3

)

=

3

2

(

x

3

)

y

+

3

=

3

2

(

x

3

)

2

y

+

6

=

3

x

9

3

x

2

y

15

=

0

Note:

The equn.of line passing through

A

(

x

1

,

y

1

)

and

with slope

m

is

y

y

1

=

m

(

x

Explanation:

the equation of a line in

slope-intercept form

is.

x

y

=

m

x

+

b

where m is the slope and b the y-intercept

rearrange

2

x

+

3

y

=

9

into this form

3

y

=

2

x

+

9

y

=

2

3

x

+

3

in slope-intercept form

with slope m

=

2

3

Given a line with slope then the slope of a line

perpendicular to it is

x

m

perpendicular

=

1

m

m

perpendicular

=

1

2

3

=

3

2

y

=

3

2

x

+

b

is the partial equation

to find b substitute

(

3

,

3

)

into the partial equation

3

=

9

2

+

b

b

=

6

2

9

2

=

15

2

y

=

3

2

x

15

2

equation of perpendicular lineExplanation:

the equation of a line in

slope-intercept form

is.

x

y

=

m

x

+

b

where m is the slope and b the y-intercept

rearrange

2

x

+

3

y

=

9

into this form

3

y

=

2

x

+

9

y

=

2

3

x

+

3

in slope-intercept form

with slope m

=

2

3

Given a line with slope then the slope of a line

perpendicular to it is

x

m

perpendicular

=

1

m

m

perpendicular

=

1

2

3

=

3

2

y

=

3

2

x

+

b

is the partial equation

to find b substitute

(

3

,

3

)

into the partial equation

3

=

9

2

+

b

b

=

6

2

9

2

=

15

2

y

=

3

2

x

15

2

equation of perpendicular line

User Zef Hemel
by
3.0k points
20 votes
20 votes

Answer:

see explanation

Explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Given

2x - 3y + 9 = 0 ( subtract 2x + 9 from both sides )

- 3y = - 2x - 9 ( divide terms by - 3 )

y =
(2)/(3) x + 3 ← in slope- intercept form

with slope m =
(2)/(3)

Given a line with slope m then the slope of a line perpendicular to it is


m_(perpendicular) = -
(1)/(m) = -
(1)/((2)/(3) ) = -
(3)/(2)

Since the equation passes through the origin then y- intercept is zero , that is c = 0

y = -
(3)/(2) x ← equation of perpendicular line

User FrakyDale
by
3.0k points