You can't just change negative numbers into positive numbers. They're completely different things.
I'm sure you worked with the number line in school. Do you remember how the negatives are on one side of zero, and the positives are on the other side ?
You dress a lot different when it's 40 degrees below zero outside, compared to what you put on when it's 40 degrees above zero. They're completely different numbers.
In the same way, 1,400 feet below sea level is the lowest spot on Earth, at the Dead Sea in Israel, but 1,400 feet above sea level is like somewhere in Nebraska or northern Texas. They're completely different numbers.
I think is 70 because you first sum 18 + 6, then your answer is 24 and you subtract 90 - 24 because the triangle is a right angle that is 90 degrees. That got me 66 and I round it to the nearest tenth and I get 70.
Plugging in (5 weeks, 40 loads) and (10 weeks, 30 loads) into each choice indicates that f(x) = -2x + 50 is the only correct answer.
If five people can do it in 12 hours, then you divide and see how long it takes each person. then you figure the rate for how many hours per person. then you figure out how many peopl it takes to do it all in 3 hours
