Question

Select the best possible first step to solving the system by first eliminating the x variable.

4x + 9y = 21
3x – 8y = 1

Choices:




A.Multiply the first equation by –3 and multiply the second equation by –4.

B.Multiply the first equation by 8 and multiply the second equation by 9.

C.None of the above

D.Multiply the first equation by 3 and multiply the second equation by 4.

Answer 1

A and D are equally 'best'

Answer 2

is the answer D?

Answer 3

i think it is

Answer 4

What would YOU do first?

Answer 5

If it is the question of "the best" step

I feel B. is the best because after multiplication and simple adding you eliminate Y

Answer 6

Personally, I'd multiply the first one by -3 and the second one by 4. But that's not one of the options. I disapprove of their use of 'best'.

Harkirat they specifically want to eliminate x, not y (who knows why)

Answer 7

according to the problem stated; A and D do the exact same thing; and B eliminates the Y so it doesnt fit the problem

Answer 8

Probably they want you to say 'None of the above' even though what I said, and A and D are basically all the same and therefore equally 'good'

Answer 9

its none of the above then right?

Answer 10

that is prolly what they want as an answer; but the real design of the question is to get you to think about what is involved and how to go about it ....

Answer 11

Can you explain to me how to get the right answer?

Answer 12

I thought we did? What part of this discussion is confusing to you?

Answer 13

The A and D part because they both sound like good options, but I don't know which one really works

Answer 14

Okay....!!
then as u said A. and D. r both equally good, provided the person knows his/her integers
otherwise D. is the better option

Answer 15

Either one can work. Either way you'd next have to subtract one equation from the other.

Answer 16

if there is only one correct answer; as opposed to a "pick all the apply", then A and D are of equal value and you can pick one over the other so both would be "wrong".

B doesnt help out in any way to eliminate the "x" so it is "wrong"

only one option left

Answer 17

gotta read thru the typo in that :)

Answer 18

oh now I get it thank you :)