Question

Find the value of c such that the system of equations

cx-16y=-5
9x-12y=-11
does not have a solution.

Answer 1

Remember that parallel lines do not intersect and so a system of parallel lines has no solution.
Remember also that parallel lines have the same slope.
What is the slope of the second line?

Answer 2

9/12

Answer 3

3/4

Answer 4

So make c a number that will cause the slope of the first line to also be 3/4

Answer 5

umm no idea

Answer 6

i dont really need to know this, we just have to do it for the class, so can you just tell me the answer?

Answer 7

please (:

Answer 8

How did you get the slope of the second line?

Answer 9

y=mx+b

Answer 10

Do that to the first line.

Answer 11

1/16?

Answer 12

cx-16y=-5
-16y=-cx-5
\[y=\frac{-c}{-16}-5\]
\[y=\frac{c}{16}-5\]

Answer 13

Make that +5/16

Answer 14

\[y=\frac{c}{16}x+\frac{5}{16}\]

Answer 15

So we see that the slope is c/16 which much be 3/4

Answer 16

And c/16=3/4
So what is c?

Answer 17

12?

Answer 18

Yes. If c =12, the lines are parallel and the system has no solution.

Answer 19

THANKS! i have two more, could you help me with those too?
please??(:

Answer 20

-9x-15y=-11
bx+20y=10

Answer 21

Same thing.

Answer 22

Try it again and I will check your work.

Answer 23

y=-3/5

Answer 24

Yes that is the slope of the first line.

Answer 25

-b/20 is the second one?

Answer 26

yes

Answer 27

does b=10?

Answer 28

\[\frac{-b}{20}=\frac{-3}{5}\]

Answer 29

\[-5b=-60\]

Answer 30

b=12

Answer 31

okay thank you so much! and the last one is
12x+dy=-3
-8x+10y=-3

Answer 32

Same thing.

Answer 33

so the slope of the first one is 4/5

Answer 34

yes

Answer 35

the second one y=-12/d - 3?

Answer 36

yes

Answer 37

d=18?

Answer 38

Actually -3/d but it doesn't affect this problem

Answer 39

wait nevermind lol

Answer 40

no

Answer 41

-12/d=4/5?

Answer 42

yes

Answer 43

so confused

Answer 44

Cross multiply.

Answer 45

15?

Answer 46

\[\frac{-12}{d}=\frac{4}{5}\]
4d=-60
d=-15

Answer 47

YAY THANK YOU

Answer 48

yw