Question

write an equation of the line that goes through the point (4,-5) and is parallelto line y=2x+8

Answer 1

@3mar

Answer 2

please help

Answer 3

So we are going to use slope intercept form. So we must use the slope of the given equation and put it in a new one \[y=2x+b\] Next we need to plug the given points into our equation, we get \[-5=2(4)+b\] Solve for b and tell me what you get.

Answer 4

Thank you for you confidence!

Answer 5

the slope is 2 and my parallel is y=2x-13

Answer 6

want me to check or answer in details?

Answer 7

yes you were right y=2x-13 is the answer

Answer 8

y=2x+8 slope is 2
y = mx + b
slope(m) = 2
(4,-5) x = 4 and y = -5
now we sub and find b, the y intercept
-5 = 2(4) + b
-5 = 8 + b
-5-8 = b
-13 = b

so parallel line/equation is : y = 2x - 13

Answer 9

correct

Answer 10

Anyway, the form of the equation of a line passes through a point\[(x_1,y_1)\] and being parallel to another line is
\[\frac{ y=y_1 }{ x-x_1 }=m\]
where m is the slope of the given line equation.

Answer 11

one more question

Answer 12

do maths, your equation is correct!

Answer 13

3,4
-1,-4
-3,2 is it a right triangle i cant tell

Answer 14

i think it is

Answer 15

Let me try

Answer 16

ok

Answer 17

Take that if you want. Decide yourself.

Are these points could make a right triangle?

Answer 18

its supposed to be 3,4 lol

Answer 19

This is how it looks.

Answer 20

its 3,4 lol

Answer 21

Sorry.
modification!

Answer 22

rhen yes lol

Answer 23

how would i explain that it is one

Answer 24

If you want to check it mathematically, simply find the slopes of every segment, if you find two of them which their product equals to -1, there will be a right triangle.
\[m_1*m_2=-1\] this is the condition of normal lines.

Answer 25

so how to do i find the slope of the segments

Answer 26

Simply
\[m=\frac{ y_2-y_1 }{ x_2-x_1 }\]
Let's try the segment AB together

Answer 27

Hey??????????

Answer 28

you get 2

Answer 29

No, brother!
It is 3.
Let's do it :]
\[m=\frac{ 3-(-3) }{ 4-2 }=\frac{ 6 }{ 2 }=3\]

Answer 30

but doesnyt it have to equal -1

Answer 31

so its not a right triangle

Answer 32

Take the second leg of the right angle (or if it would be):
slope of BC:
\[m_{BC}=\frac{ -4-2 }{ -1-(-3) }=\frac{ -6 }{ 2 }=-3\]

Answer 33

so it is a right triangle

Answer 34

because all slopes equal the smae

Answer 35

am i rigth

Answer 36

if you dont hurry im goign with it

Answer 37

It is.

How could you let me made this mistake?

The slope is y/x not x/y
\[m=\frac{ \Delta y }{ \Delta x } \]

not
\[m=\frac{ \Delta x }{ \Delta y }\]

Answer 38

Sorry Sorry Sorry

Answer 39

so is it or is it not a right triangle

Answer 40

i have to go mow soon

Answer 41

Two slope are 1/3 and -3.
So they are perpendicular to each other.
There is a right angle in the triangle.
Done!

Answer 42

so its not a right triangle