Question

12x+13y=12.01

x+y=2.323 times 10 to the 27 power
x= # of carbon - 12 atoms
y= # of carbon- 13 atoms
solve for x and y
Please help!!!!!

Answer 1

`y = - 2.7876 * 10^(28)`

`x= 3.0199 * 10^(28)`

Step-by-step explanation:

Given

`12x+13y=12.01`

`x+y=2.323 * 10^(27)`

Required:

Solve

Make x the subject in
`x+y=2.323 * 10^(27)`

`x=2.323 * 10^(27) - y`

Substitute the above expression for y in
`12x+13y=12.01`

`12(2.323 * 10^(27) - y) + 13y = 12.01`

Open brackets

`12*2.323 * 10^(27) - 12y + 13y = 12.01`

`12*2.323 * 10^(27) + y = 12.01`

Collect Like Terms

`y = 12.01 - 12*2.323 * 10^(27)`

`y = 12.01 - 2.7876 * 10^(28)`

12.01 is negligible compared to
`2.7876 * 10^(28)`

So:

`y = - 2.7876 * 10^(28)`

Substitute the above expression for y in
`x=2.323 * 10^(27) - y`

`x=2.323 * 10^(27) - (- 2.7876 * 10^(28))`

`x=2.323 * 10^(27) + 2.7876 * 10^(28)`

`x= 0.2323 * 10^(28) + 2.7876 * 10^(28)`

`x= 3.0199 * 10^(28)`