Answer:
0
Step-by-step explanation:
0 is the identity element under addition for the real numbers.
The probability of picking a black ball first is

, because there are 4 black balls and 1 white ball which is 5 balls in total. After picking the first ball, 4 balls remain - 3 black and 1 white, so the probability of picking a white ball is

.
So, the probability of picking a black ball first followed by a white ball is
1. square base area= 25 inches
2. using the slanted 6.5
=1/2base , therefore 5/2=2.5 inches
3. then use pythagoras.... c=6.5, a=2.5
c^2=a^2 + b^2
(do this urself)
4. when u find what b is... that's the height of one of the triangle
base= 2.5 (look at step 2 if u don't understand this bit)
height=b (refer to step 3)
5. then work out the area of 1 triangle using that...
6. then have (the answer u work out in step 5 ) multiply 4
this will give u the area for the all of the 4 triangles...
7. Then add together the square based area in step 1..(25)
to the 4 triangular, area faces (i.e from step 6) - the total will be ur answer for the amount of cardboard!!
p.s don't forget the units!!!
I think the correct answer is b
X+y=-10/11 is in standard from