Answer:
a=4, b=5/2
Step-by-step explanation:
Assuming the given equation is

We expand the left hand side to get:

If this equation must have infinitely many solutions, then

Also we must have

Put a=4 to get:


Cos 28 = 18/ y
so
y = 18 / cos 28
y = 18 /.8829
y = 20.4
X + (f + g) = <span>(x + f) + g
Last choice</span>
Answer:
Answer choice B
Step-by-step explanation:
There are two possibilities; in the first, the first digit is below 5, in the second, it is above. The probability of the first possibility is 3/8, because there are 3 possible digits below 5 and 8 total digits. In this scenario, the chance of the second digit being below 5 is 2/7, because one of the digits is taken. In the other possibility, which has a chance of 5/8, the probability of choosing a number below 5 is 3/7, since all of them are still available. Doing the arithmetic, you find that the total probability is 2/7. Hope this helps!
Since we already know that the older child is a girl (a 100% chance to be a girl), there must be a 50% chance that the other child is a girl. Therefore, the probability that both children are girls is 50%.
Hope this helps!