Question

2500 = x(0.045) + y(0.06)
find x, find y

Answer 1

Is this supposed to be in parametric form, or is there a second equation?

Answer 2

guess so? its just 2500 = x(0.045) + y(0.06)

Answer 3

Hmmm.... because all that does is define a singe line. Perhaps they want it solved for x and solved for y.

Answer 4

yup

Answer 5

OK. Then you need to basically work with your order of operations, but from bottom up!

Answer 6

uh...?

Answer 7

Well, you know the order of operations? PEMDAS?

Answer 8

oh

Answer 9

so 2500 = x(.045) + y(.06)
x = -(2500-0.6y)/0.045 right?

Answer 10

hmmmm....
\(2500 = x(.045) + y(.06)\implies \\
2500-y(.06) = x(.045) + y(.06)-y(.06)\implies \\
2500-y(.06) = x(.045)\implies \\
\left[2500-y(.06)\right]/(.045) = x(.045)/(.045)\implies \\
\left[2500-y(.06)\right]/(.045) = x
\)

\(\therefore x=\cfrac{2500-y(.06)}{.045}\)

Answer 11

Not sure how you got the - in front.

Answer 12

I tried that but it x turned to zero(0) (and so did y)

Answer 13

Well, an x of 0 does exist in that solution. So does a y of 0. That is, in that form, the answer for x.

Answer 14

but it wouldn't be equal to 2500

Answer 15

2500+0=2500

In this particular case, because of the decimals, the intercepts are at much larger numbers. This is the equation of a line.

http://www.wolframalpha.com/input/?i=2500+%3D+x%280.045%29+%2B+y%280.06%29&dataset=

Answer 16

oh, thank you :)

Answer 17

So to find y, just do the same sort of moving things around. If there was a second equation for a second line, and they crossed, there would be one x and one y. But with just one equation, all you have is a line.

Answer 18

can x be also be found using derivatives?

Answer 19

All you will get with a derivative is the slope.

Answer 20

oh, thank you:)