He multiplied rather than dividing.

Hope this helps!
Answer:
y=-3/2x+5
Step-by-step explanation:
3x+2y=10
2y=10-3x
2y=-3x+10
y=-3/2x+10/2
y=-3/2x+5
900 because you have to add 24 squared + 18 squared
Answer:

Step-by-step explanation:
I suggest looking lessons on it online if you don't understand... It's hard to do your work especially if you don't understand it. Or if your online, go to past lessons or something.
Answer:
3.5 mi = 18480 ft
Step-by-step explanation:
There are 5,280 feet for every one mile. Because there are 3.5 mile, you would multiply 5,280 x 3.5, getting 18480 feet.