Answer:
a. f(x)=58-5(x-1); there are 58 boxes in the top row.
b. 273 boxes
Step-by-step explanation:
There are 33 boxes at the bottom row, and there are 5 fewer boxes than the row before it meaning that each row above the bottom row has five more boxes than the one below it.
Basically:
bottom row (with 33 boxes) -->5th row-->4th row-->3rd row-->2nd row-->1st row
each arrow adds five boxes, so if you add 5 boxes for each arrow, there is a total of 58 boxes on the 1st row.
check:
2nd row:
f(x)=58-5(x-1)
f(2)=58-5(2-1)
f(2)=58-5(1)
f(2)=58-5
f(2)=53
and we know that 58 (first row)-5=53 (second row; has to have five fewer boxes) so the function works.
now we can use the formula to find the other row values:
3rd row:
f(x)=58-5(x-1)
f(3)=58-5(3-1)
f(3)=58-5(2)
f(3)=58-10
f(3)=48
4th row:
f(x)=58-5(x-1)
f(4)=58-5(4-1)
f(4)=58-5(3)
f(4)=58-15
f(4)=43
5th row:
f(x)=58-5(x-1)
f(5)=58-5(5-1)
f(5)=58-5(4)
f(5)=58-20
f(5)=38
so, we have the row values from top to bottom:
58, 53, 48, 43, 38, 33
now we just have to add them up, giving us 273 boxes in total.
