Answer:
The speed of the biker is 15
Step-by-step explanation:
First, you call the speed of the walker x, and the speed of the biker 2.5x.
Then you know that speed times time equals distance, so you set up and equation. You do x times 2, which is 2x, and then 2.5x times 2, which is 5x. Then, since the distance between them is 18 miles, the equation would be 5x-2x=18. You would get 3x=18, and x is 6. So 6 is the speed of the walker, and 6 times 2.5 = 15, so the speed of the biker is 15.
It will take 45 weeks.25 weeks to gain back the 500 dollor he spent and 20 to make 400 dollor from it
Answer:
Step-by-step explanation:
4u + 8v = -3u + 2v
Solving 4u + 8v = -3u + 2v
Solving for variable 'u'.
Move all terms containing u to the left, all other terms to the right.
Add '3u' to each side of the equation. 4u + 3u + 8v = -3u + 3u + 2v
Combine like terms: 4u + 3u = 7u 7u + 8v = -3u + 3u + 2v
Combine like terms: -3u + 3u = 0 7u + 8v = 0 + 2v 7u + 8v = 2v
Add '-8v' to each side of the equation. 7u + 8v + -8v = 2v + -8v
Combine like terms: 8v + -8v = 0 7u + 0 = 2v + -8v 7u = 2v + -8v
Combine like terms: 2v + -8v = -6v 7u = -6v
Divide each side by '7'. u = -0.8571428571v
Simplifying u = -0.8571428571v
Round to tens: 240 + 370 = 610
round to hundreds: 200 + 400 = 600
hope this helps