No, that is not correct. The percentage only applies to that part of the taxable income which more than $20000. You should use f(x)= 0.0685(x- 20000)+ 973.

Yes, the taxable income is T(x)= 0.8x. Assuming that is between 20000 and 100000, then the tax would be 0.0685(.8x- 20000)+ 973.For b) Since they didn't give me a real income to go on, I just wrote out the formula for whatever the lawyer's income could be which is T(x) = 0.8(x), x = income. I don't know if that is correct by multiplying it by 0.8 or should the formula be T(x) = x - 20000, x = income. Please check if this is correct.

Yes, although it would be better to write explicitely thatFor c) L(x) = (T(x) - 20000)(0.0685) + 973

Please check if this formula is correct

L(x)= 0.0685(0.8x- 20000)+ 973.

Yes, that would be correct.For d) I just used the above formula and placed in 85000 for x.

Thanks in advance