Say you want to create a ladder. Why would it be important to know if lines are parallel or perpendicular to each other?

thats one

step-by-step explanation:

60: 45 =12: 9 =4: 3 so the answer is 4: 3

answer:

at time x=0 we have 1000, at time x=1 we have 2000, at time x=2 we have 4000.  

so that's an initial value of 1000 and a ratio of 2,

y = 1000 (2^x)

hope this !