Answer:
The correct answer is 1/49
Step-by-step explanation:
In order to find this, we first can eliminate the negative in the exponent by putting the whole this in the denominator.
(-7)^-2 = 1/(-7)^2
Now we can evaluate the denominator
1/(-7)^2 = 1/49
Answer:
a set of two or more equations, each containing two or more variables whose values can simultaneously satisfy both or all the equations in the set, the number of variables being equal to or less than the number of equations in the set.
Step-by-step explanation:
It works because of two properties of equations: Multiplying (or dividing) the expression on each side by the same number does not alter the equation. Adding two equations produces another valid equation: e.g. 2x = x + 10 (x = 10) and x − 3 = 7 (x also = 10).
Answer:
The probability of selecting a black card or a 6 = 7/13
Step-by-step explanation:
In this question we have given two events. When two events can not occur at the same time,it is known as mutually exclusive event.
According to the question we need to find out the probability of black card or 6. So we can write it as:
P(black card or 6):
The probability of selecting a black card = 26/52
The probability of selecting a 6 = 4/52
And the probability of selecting both = 2/52.
So we will apply the formula of compound probability:
P(black card or 6)=P(black card)+P(6)-P(black card and 6)
Now substitute the values:
P(black card or 6)= 26/52+4/52-2/52
P(black card or 6)=26+4-2/52
P(black card or 6)=30-2/52
P(black card or 6)=28/52
P(black card or 6)=7/13.
Hence the probability of selecting a black card or a 6 = 7/13 ....
