7.
two urns each contain green balls and black balls. um i contains four green balls and six black balls and um ii
contains five green balls and three black balls. a ball is drawn from each urn at random. what is the probability
that both balls are black?

4sqrt5

step-by-step explanation:

the base has dimensions of 8 x 4, so the diagonal is 64 + 16 square rooted or 4sqrt5.

step-by-step explanation:

the ratio of red paint to blue paint is always 9/7. that means that, whatever x's value, (4x+12)/(4x-4) has that same ratio. so, set up an equation and cross-multiply to solve for x:

9/7 = (4x+12)/(4x-4)

9(4x-4) = 7(4x+12)

36x - 36 = 28x + 84

8x - 36 = 84

8x = 120

x = 15

2y+y=5

add 2y and y

actually what is a question i don't understand