The work is on the picture attached, but a = 1
Hope this helps!!
I think its 1000 numbers because there from 1 to 999 there are 999 numbers, and then you add zero because it is also a whole number.
Answer: y = x + 10
Explanation: substitute x by the numbers in the first column and add that by 10 which would be equal to the numbers in the second column (y) for example 1+10= 11
Each shrub would cost $9.
x=(53.50-17.50)/4
Hope I help!!!