Answer:
The probability of picking a black card at random, from a deck with 3 black cards and 7 red ones is 0.3.
Step-by-step explanation:
We will assume that we have 3 black cards and 7 black cards, for a total of 10 cards. Since we are taking one card at random, we can assume that each card is equally likely to be drawn. We have the following event A: The drawn card is a black. We will find the probability of A as counting the number of outcomes that make A to occur and divide it by the total number of possibilities. We are drawing one card, so we have 10 possibilities to be picked. Out of those 10, only 3 cards are black, hence we have 3 possibilites of picking a black card.
Then,
P(A) = 3/10 = 0.3.
it isn't the first 2 options
I'd say it's y=1/2x - 2
Answer:
A choice
Step-by-step explanation:
sec is defined as 1/cos.
cos is again defined as adjacent to hypotenuse.
We know that adjacent is x and hypotenuse is r.
Therefore:- cos is x/r
Now sec is 1/cos = 1/(x/r)
1 ÷ x/r is 1•r/x
Thus:-
sec is r/x
Given the quadratic function, to get the roots we factorize:
3x²-4x-7=0
3x²+3x-7x-7=0
3x(x+1)-7(x+1)=0
(3x-7)(x+1)=0
thus the roots are
x=-1 or x=3/7
thus the sum of the roots will be:
-1+3/7
=-4/7
