Answer:
285 boxes are in the display
Step-by-step explanation:
Given data
top layer box = 1
last row box = 81
to find out
how many box
solution
we know that every row is a square so that if the bottom layer has 81 squares it mean this is 9² and every row has one lesser box
so that next row will have 8^2 and than 7² and so on till 1²
so we can say that cubes in the rows as that
Sum of all Squares = 9² + 8² +..........+ 1²
Sum of Squares positive Consecutive Integers formula are
Sum of Squares of Consecutive Integers = (1/6)(n)(n+1)(2n+1)
here n = 9 so equation will be
Sum of Squares of Consecutive Integers = (1/6) × (9) × (9+1) × (2×9+1)
Sum of Squares of Consecutive Integers = 285
so 285 boxes are in the display
Year Sam Sally1: X (3/2)X-10002: (5/2)X-2000 2X-15003: X/5+1000 X/4+1400Total 37X/10-1000 15X/4-1100
Since their investments are known to be equal, we equate the two totals and solve for X.37X/10-1000=15X/4-1100(150-148)X/40 = 1100-1000X/20=100X=2000
So Sam invested $2000 the first year.Sally invested X/4+1400=1900 in the last year.
This is very spread out just to show properly but you could get it smaller haha
Answer: 2
<u>Explanation:</u>
A pond had 60 fish but 10 were added so now the pond has 70 fish.
The probability of choosing a carp is 1/2 so 
= 35 are now carp.
There were 27 carp and now there are 35 carp so 8 carp were added.
10 fish were added and 8 of them were carp so 2 of them were tench.
X2+7x-8=0
product=-8 times 1 = -8
sum= 7
{-1, 8}
x2-1x+8x-8=0
x(x-1)+8(x-1)=0
x+8=0 or X-1=0
x=-8
