Question

What is a possible first step to eliminate a variable in the following system?
2x – 3y = –1
3x – 4y = –3

a. Multiply the first equation by –3 and the second equation by 2.

b.Multiply the first equation by 3 and the second equation by –2.

c.Multiply the first equation by –4 and the second equation by 3.

d.All of the above.

Answer 1

you want to figure out which of these actions will get the coefficients of at least one of the variables to be equal and opposite

for example

ax+by=c
-ax+py=q we can add these:
__________
(b+p)y=c+q

Answer 2

notice that eliminated the x variable because the first had coefficient a and the second had -a

Answer 3

so try each out
what do you get when you

a. Multiply the first equation by –3 and the second equation by 2.

?

Answer 4

i got a to

Answer 5

a "to" ?

Answer 6

im answer that i got was a

Answer 7

ok, why do you think it's a ?

Answer 8

I was just asking you to try it out ans see what you get
try doing what (a) says, and write what you get after those operations
what are the two equations now?

Answer 9

I'm in no way suggesting that a is the right answer

Answer 10

is it c

Answer 11

It kinda seems like you're just guessing unless you can tell me why you think a particular answer is right, so I'm not going to confirm or deny anything yet.
Please explain your reasoning and hopefully I can help you better

Answer 12

what do you get by multiplying the first equation by -3 ?