Oh, I remember this one. Here's this if you need it, if it doesn't help then let me know.
Answer:
1. 
2. 
3. 
Step-by-step explanation:
<h3> The complete exercise is: "Brown rice costs $2 per pound, and beans cost $1.60 per pound. Lin has $10 to spend on these items to make a large meal of beans and rice for a potluck dinner. Let b be the number of pounds of beans Lin buys and r be the number of pounds of rice she buys when she spends all her money on this meal.</h3><h3>1. Write an equation relating the two variables.</h3><h3>2. Rearrange the equation so "b" is the independent variable.</h3><h3>3. Rearrange the equation so "r" is the independent variable."</h3><h3 />
1. According to the information exercise given in the exercise, the cost per pounds of brown rice is $2. Since "r" represents the number of pounds of rice Lin buys, the total cost of the brown rice she buys can be represented with this expression:

The beans cost $1.60 per pound. Since "b" represents the number of pounds of beans Lin buys, the total cost of beans she buys can be represented as:

Knowing that she spends $10, you can write the following equation:

2. In order to rearrange the equation so "b" is the independent variable, you need to solve for "r":

3. To rearrange the equation so "r" is the independent variable, you must solve for "b". You get:

Answer: The total length in kilometers is 38 km
Step-by-step explanation:
17 + 2 = 19 km is 1/2 of the total length, that is,
19 = (1/2)h
(1/2)h = 19 multiply both sides by 2
h = 2*19
h = 38 km
Add it. average= sum of 2 counts/2