Answer:
The answer is 4z^2 + 7z
Step-by-step explanation:
7z + 4z^2 +6 - 6
So, just combine like term which is 6 - 6 = 0
So, the remaining is 4z^2 + 7z that cannot be simplified anymore
Ok if you show me the question I can try to help but you got to show it
I have included a picture. In the picture you will find the work and final answer.
Assuming that the probability of boys and girls is equal (in reality slightly more boys than girls are born), the probability is 1/2, simply because the older girl's gender is given and therefore not a part of the probability.
This question comes from the 'boy or girl paradox', a.k.a. the Mrs Smith Problem.