Question

PLease explain this equation of lines http://gyazo.com/0b74c6b05d3b6c19a6ff63a65430e48a.png

Answer 1

write the first line in y=mx+c take m from 1st eqn and write the 2nd eqn as y=mx+b den plug in the points and get the value of b

Answer 2

I don't understand

Answer 3

I know the first equation is y = 8/3x + 7

Answer 4

Am I just supposed to multiply the x from the given point to the 7 in the equation?

Answer 5

@ganeshie8 would you help me?

Answer 6

first equation shud be :-
y = 8/3x - 7
^^

Answer 7

since we want a line parallel to above guy,
both must have the same slope

Answer 8

so slope of the require line = m = 8/3

Answer 9

fine so far ? :)

Answer 10

say the required line is,
y = mx + b

plugin the m value

y = 8/3x + b

Answer 11

you need to find the value of 'b' still,
any ideas how to find b ?

Answer 12

No

Answer 13

use the given info :-
the required line passes thru (7, -8)

Answer 14

so it has to satisfy that point (7, -8)

y = 8/3x + b

put x = 7, y = -8 and solve for b

-8 = 8/3*7 + b

solve b

Answer 15

-8 = 56/3 + b ?

Answer 16

yup, keep going, solve b

Answer 17

next step, get rid of denominator.

multiply thru by 3

Answer 18

-8 = 56/3 + b

multuply thru by 3

-8*3 = 56 + 3b

-24 = 56 + 3b

Answer 19

can u take it from here ? :)

Answer 20

b = -80/3 ?

Answer 21

Correct !

Answer 22

put that value of b in our original equation :-

y = 8/3x + b


y = 8/3x - 80/3

Answer 23

you may have to change it to standard form again

Answer 24

that shud be easy

y = 8/3x - 80/3

multiply thru by 3

3y = 8x - 80

add 80 both sides

3y + 80 = 8x

subtract 3y both sides

80 = 8x - 3y

its same as :-

8x - 3y = 80

Answer 25

Thank you again :)

Answer 26

np :)