5000-x is the number of dollars in the mutual fund
Step-by-step explanation:

The total cost when 881 minutes is used is $477.50.
<h3>What are the equation that model the question?</h3>
a + 480b = 277 equation 1
a + 990b = 532 equation 2
Where:
- a = flat fee
- b = variable fee
<h3>What is the flat fee and the variable fee?</h3>
Subtract equation 1 from equation 2
510b = 255
b = 255 / 510
b = $0.50
In order to determine the flat fee, substitute for b in equation 1
a + 480(0.5) = 277
a + 240 = 277
a = 277 - 240
a = $37
<h3>What is the total cost when 881 minutes is used?</h3>
Total cost = flat fee + (variable cost x number of minutes spoken)
$37 + (881 x 0.5) = $477.50
To learn more about simultaneous equations, please check: brainly.com/question/25875552
#SPJ1
to get the numbers in step 3
multiply -1.6 by 3
then multiply -1.6 by 0.1
and add them together
answer is D) (–1.6)(3) + (–1.6)(0.1)