Step-by-step explanation:

We know that the midpoint is the a point in the center of the line (r). This means that from the midpoint to the endpoint (qr) is half the length of the overall line. This means that 5.7 (the length of qr) units is half the length of the line. Two halves make a whole so 5.7 × 2 = 11.4 units as the length of the entire line qs.
Hope this helps!
Answer:
Step-by-step explanation:
To solve this, we are going to make an age table:
Age Now Age 10 years ago
Tanya
Elliot
Filling the in the Age Now column comes from the first sentence. If Elliot is 2 times Tanya's age and we don't know Tanya's age, then Tanya's age is x and Elliot's age is 2x:
Age Now Age 10 years ago
Tanya x
Elliot 2x
Filling in the Age 10 years ago column simply requires that we take their ages in the Age Now column and subtract 10 from each age:
Age Now Age 10 years ago
Tanya x x - 10
Elliot 2x 2x - 10
Since the question is How old is Elliot now based on the fact that 10 years ago....blah, blah, blah, we are using the ages in the 10 years ago column to write our equation. It says:
10 years ago, Elliot was 4 times as old as Tanya. Translated into mathspeak:
2x - 10 = 4(x - 10) and
2x - 10 = 4x - 40 and
-2x = -30 so
x = 15. That means that Elliot is 30 and Tanya is 15
The maximum profit would be $1325. Since they make less profit on deluxe seats, you want to get as few of those as possible. You also want to get as many people on the boat as possible, which is 45. The minimum number of deluxe seats you could sell is 5, so that's what we'll use for the max. profit. They make $25 off of each of those seats so 5 times $25 is $125. That leaves 40 economy seats, with a profit of $30 per seat. You have 40 spots left open, so we'll sell 40 economy seats, which will meet your minimum of 14 economy seats. 40 times $30 is $1200. Add $125 and $1200 to get $1325 and you have your maximum profit!