Conuert to a fraction 6,8%

A salesperson earns $50 a day plus 12% commission on sales over $200. If her daily earnings are $76.88, how much money in merchandise did she sell?

The amount owed at the end of 5 years.
An amount of ${\displaystyle \mathrm{\$}3000}$ is loaned at a rate of $10\mathrm{\%}$compounded quarterly.

Find the zeros (if any) of the function ${\displaystyle y=x^4+3x^2+2}$ algebraically.

What does it mean: the product of two ideals I and J is the set of all finite sums of elements of the form ab with ${\displaystyle a\in I}$ and ${\displaystyle b\in J}$?

Translate each statement into a linear equality or inequality then solve algebraically.
1. Seven more than three times a number equals eight less than four times the number.
2. Twelve minus nine times a number is the same as two minus eight times the number.
3. Five minus two times x is less than or equal to seven minus three times x.

${\displaystyle 2(y-4)\leftarrow 18}$

Sun-Yi estimated 270 + 146 and got 320. Is her estimate reasonable? Explain.