Answer: the fixed amount that Daria earns for each television is $70
Step-by-step explanation:
Let x represent the fixed amount that Daria earns for each television.
She earns a fixed amount for each television and an additional $30 if the buyer gets an extended warranty. This means that if she sells n televisions with extended warranties, the total amount that she would earn is
xn + 30n
If Daria sells 11 televisions with extended warranties, she earns $1100. This means that
11x + 11 × 30 = 1100
11x + 330 = 1100
11x = 1100 - 330
x = 770/11
x = $70
