Question

help please !!

1.)How many solutions does the system of equations have
15y-3x+9
y=-1/5x+9/15

a.)one**
b.)two
c.)none
d.)infinitely many

2.) what is the slope of the line that passes through the pairs of points ?
(-2,1),(2,17)

a.)4/17
b.)-15
c.)-4**
d.)4
@Qwertty123

Answer 1

Yes hello!

Answer 2

helloo

Answer 3

Guess what another link just for you! It is really easy once you got it! https://www.desmos.com/calculator there you go!

Answer 4

ive tried that link and it dont help as much

Answer 5

did you put in the two equations in two different lines?

Answer 6

@Little.cherry23

Answer 7

yes id did i just dont clearly under stand how to use that

Answer 8

oh well you put in the equations then you hover where the two lines intersect... okay?

Answer 9

i think the answers are b and d

Answer 10

and how did you get that

Answer 11

@Improvement Don't give direct answers!

Answer 12

a quick check you can always do,
-any multiple of a linear equation is the same line, like this

x + 2y = 1
5x + 10y = 5

same lines

Answer 13

so its b and d ?

Answer 14

ive been at this for 6 hours

Answer 15

He is so correct! @DanJS

Answer 16

there is a quick orthogonal test with the dot product

Answer 17

?

Answer 18

What?

Answer 19

also how would you graph >5x-2 or <5y-2 ??

Answer 20

15y = 3x+9
y=-1/5x+9/15

i just mentioned that check, because here, you can notice the second equation is just 1/15 of the first, a multiple of each other, same lines, overlap infinitly many times

Answer 21

graph it the same as an equality, except dotted lines for > and < if not also equal to, then shade the right area according the the inequality

Answer 22

i am correct

Answer 23

can i have a medal plz i need some

Answer 24

two lines can not intersect twice, there will always be
-1 unique solution at the intersection (x,y)
- 0 solutions, for parallel non intersecting lines
- infinity , for a system like this prob where they are the same overlapping line

Answer 25

Your correct for what @Improvement

Answer 26

i knew i was

Answer 27

solving the system for parallel or same lines will not result in any variable values for x or y,
usually, if you get a false statemtnt, like 5 = 8, then it is no solution, parallel
if you get a true statemtn like 5=5, then same lines, infinity solutions

Answer 28

I knew I was.... what? @Improvement

Answer 29

b and d, , the first is not 'two'

Answer 30

i think it is

Answer 31

dan just think

Answer 32

I think she got the answers already! :)

Answer 33

a system of two linear equations will not have two solutions,
1,0,or infinity

Answer 34

draw two lines and have them intersecting twice, then i will believe it

Answer 35

What number are you on @DanJS

Answer 36

how do you put -4 >32 on a line graph @im

Answer 37

wait dan let me check again

Answer 38

it looks like everyone is saying two for the first prob, they are the same lines, infinity is the correct choice

Answer 39

lets see mabey im wrong

Answer 40

wait a sec

Answer 41

You cant @Little.cherry23 that line can't be graphed! :/

Answer 42

any x and y value will work in both of them

Answer 43

x=-4/5y+3
4x-5y=-15

a.)parallel
b.)perpendicular
c.)neither

Answer 44

That one you can do! You can graph then both!

Answer 45

im not sure if the x and y values are right because alot of them are cut out my questions so its really hard to answer my questions

Answer 46

yeah i think dan is right this time

Answer 47

Hey Improvement how many medals do you have?

Answer 48

not many ussually dont help i just started

Answer 49

help me get some???

Answer 50

dan is the very top two questions d and d ?

Answer 51

I will give you a medal @Improvement for trying to help her out! :D

Answer 52

yes its d and d

Answer 53

thx

Answer 54

can everyone in here give me a medal lol

Answer 55

no @Improvement ! :) I medal you can only give away. I think @Little.cherry23 gave hers away.

Answer 56

yes, for this other one

x = -4/5y + 3
4x - 5y = -15
--------------
you can compare slopes in the y=m*x+b form, same is parallel negative recipricle is perpendicular,
or

both in standard form

5x + 4y = 15
4x - 5y = -15
-----------
notice 5*4 + (4*-5) = 0, if you do that pattern and get zero, they are perpendicular
(vector dot product being zero) but forget that

Answer 57

So true!

Answer 58

<a,b>*<c*d>, direction vectors , dot product is zero if they are perpendicular

from standard form for the lines Ax + By =C just multiply the two x coefficients and add that to the product of the two y coefficients,
quick check to say perpendicular lines if you get a zero,

Answer 59

dan can u answer a couple of my questions