math

writing equation of lines

100

(6,-2);m=3

what is slope?

3

200

(0,-9)'m=7

what is y axis intercept?

-9

300

write and solve in intercept form 

(6,-2);=3

y=3x-20

400

write and solve in intercept form 

(0,-9)'m=7

y=7x-9

500

write and solve in intercept form

(4,-8);m=-1/2

y=4x-6

slope intercept form

100

write in intercept form

slope=1, y-intercept= 0

y=1x

200

write in intercept form 

slope=4, y intercept=-4

y=4x-4

300

write intercept form

slope=3, y intercept=-3

y=3x-3

400

write in intercept form 

slope=1/2, y intercept=-1

y=1/2x-1

500

write intercept form 

slope=-3/2, y intercept=-2

y=3/2x-2

point slope

100

(2,5) slope is 5

in point slope 

y-y1=m(x-x1)

y-5=5(x-2)

y-5=5x-10

y=5x-5

200

point slope 

slope=8

(5,9)

y-y1=m(3,7)

y-9=8(x-5)

y-9=8x-40

y=8x-31

300

point slope form 

slope=4

(7,9)

y-y1=m(x-x1)

y=4x-19

400

point slope form 

slope= 9

(8,9)

y-y1=m(x-x1)

y-9=9(x-8)

y-9=9x-72

y=9x-63

500

find slope then write it into a point slope form (2,4) (4,9)

slope=5/2

y=5/2x-1

spot the error

100

Spot the error!

Write the equation of the line that passes through (2, 1) with slope = 4.

y=4(2)+1

y=8+1

y=9

This means the equation is y=4x+9

Number 1 is not the "b" it is the "y"

1=4(2)+b 

1=8+b

-7=b

answer is y=4x-7

200

spot the error 

write the equation of the line that passes through (5,2) with the slope of 2

5=2(2)+b

5=4+b

1=b

this means the equation is y=2x-4

The "x" and the "y" are switched 

2=2(5)+b

2=10+b 

-8=b

the answer is: y=2x-8 

300

spot the error 

write an equation in the line in the form slope/intercept.

(8,2) m=3

2-y=3(x-8)

2-y=3x-24

 the answer is -y=3x-26

the first y is not suppose to be switched its suppose to be y1

y-2=3(x-8)

y-2=3x-24

y=3x-22

400

spot the error 

write an equation in the line in the form slope/intercept.

(2,2) slope=3

y-2=3(x-2)

y-2=3x-6

y=3x-8

the adding is wrong 

500

spot the error! 

write an equation of the line, in the form slope/intercept.

(2,3) m=-2

y-3=-2(x-2)

y-3=-2x+-4

y=-2x-1

the 4 should not be negative 

making the problem y=y-2+1

extra problems

100

find b (2,4) when slope=2

y=mx+b

4=2(2)+b

4=4+b

0=b

200

if slope was 3/4 what would be the perpendicular of it?

-4/3

300

slope=4 put this into a point slope of the line (3,9)

y=4x+6

400

find the slope of the coordinates (2,7) (3,2)

slope equals -5

500

find slope then put into point slope form 

(4,7)   (6,9)

y=1x+3