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
Recall that the equation to find the perimeter of a rectangle is 2(L + w)
Since we know the length, we can make an equation:
2(3 + w) = 12
Divide both sides by 2:
(3 + w) = 6
w = 3
Now that we know both length and width, we simply have to find their product to solve for area:
a = L * w
a = 3 * 3
a = 9
The area of the rectangle is 9 cm^2.
The slope between 2 points (x1,y1) and (x2,y2) is
(y2-y1)/(x2-x1)
so
(y2-y1)/(x2-x1)=-5/7
y2-y1=-5
x2-x1=7
this is easy, if x1=0 and y1=0, then x1=7 and y2=-5
(0,0) and (7,-5) is a possible point
