how do i solve this?

.10=.9(x/15000)+.14(1-x/15000)

Multiply it out and combine terms.

0.10 = 6*10^-5 x + 0.14 - 9.333*10^-6 x
-0.04 = 5.067*10^-5 x
etc.

what if I change the 1-x to a y?

how do you solve for 2 variables?

You need to have an equation with one variable to get a solution. Why create a new variable?

You end up with two variables and two equations, and are just adding more work to the problem.

By the way, if your original equation has 1-x as a numerator, then you should have written it
.10 = .9(x/15000)+ .14(1-x)/15000,
and you'd get a different answer.

To solve the equation, you would start by simplifying and rearranging the terms. Here's how you can do it step by step:

1. Distribute the coefficients to each term inside the parentheses:
- .10 = .9(x/15000) + .14(1 - x/15000)

2. Simplify each term inside the parentheses:
- .10 = .9 * (x/15000) + .14 * (1 - x/15000)

3. Simplify the expressions within each term:
- .10 = .9x/15000 + .14 * (1 - x/15000)

4. Distribute the .14 coefficient to the terms within the parentheses:
- .10 = .9x/15000 + .14 - .14x/15000

5. Combine like terms on the right side of the equation:
- .10 = (.9x - .14x)/15000 + .14

6. Combine like terms on the left side of the equation:
- .10 = .76x/15000 + .14

7. Move .14 to the left side by subtracting it from both sides:
- .10 - .14 = .76x/15000

8. Simplify the left side:
- (-.04) = .76x/15000

9. Multiply both sides by 15000 to eliminate the denominator:
- 15000 * (-.04) = .76x

10. Simplify the left side:
- (-600) = .76x

11. Divide by .76 to solve for x:
-600 / .76 = x
-789.47 = x

Therefore, the solution to the equation is x = -789.47.