The domain is defined as the complete set of values of variable x for which the function is valid. In this case, the x-axis illustrates time in seconds. Therefore, we must determine all possible time values over which distance can be covered or the function is defined. It’s noted that the sprinter completed the race in 11 seconds, and the start time is 0 seconds. Hence, the value of t ranges from 0 to 11. Therefore, the domain encompasses all real numbers from 0 to 11.
Typically, the graph will have a labeled line such as f(x) = ... To find f(3), identify 3 on the x-axis, then trace vertically to the graph line and read the corresponding y-value.
Part A
To identify the values of x that make 2x−1 positive
⇒ 2x - 1 > 0
⇒ 2x > 1
⇒ x > 
As a result, for any x greater than
, the expression 2x-1 is positive
Part B
To find values of y making 21−37 negative
⇒ 21-3y < 0
⇒ 21 < 3y
⇒ 7 < y
Thus, for all y values exceeding 7, the expression 21-3y is negative
Part C
To identify values of c that digit 5−3c greater than 80
⇒ 5-3c > 80
⇒ -3c > 75
⇒ -c > 25
⇒ c < -25
Therefore, for values of c less than -25, the expression 5-3c surpasses 80
I will designate the hourly rate for weekdays as x and for weekends as y. The equations are arranged as follows:
13x + 14y = $250.90
15x + 8y = $204.70
This gives us a system of equations which can be solved by multiplying the first equation by 4 and the second by -7. This leads to:
52x + 56y = $1003.60
-105x - 56y = -$1432.90
By summing these two equations, we arrive at:
-53x = -$429.30 --> 53x = $429.30 --> (dividing both sides by 53) x = 8.10. This represents her hourly wage on weekdays.
Substituting our value for x allows us to determine y. I will utilize the first equation, but either could work.
$105.30 + 14y = $250.90. To isolate y, subtract $105.30 from both sides --> 14y = $145.60 divide by 14 --> y = $10.40
Thus, we find that her earnings are $8.10 per hour on weekdays and $10.40 per hour on weekends. The difference shows she earns $2.30 more on weekends than on weekdays.
