Answer: 
Step-by-step explanation:
We know that the standard quadratic equation is ax^2+bx+c=0
Let's compare all the given equation to it and , find discriminant.
1. a=2, b= -7, c=-9
So it has 2 real number solutions.
2. a=1, b=-4, c=4

So it has only 1 real number solution.
3. a=4, b=-3, c=-1

So it has 2 real number solutions.
4. a=1, b=-2, c=-8
So it has 2 real number solutions.
5. a=3, b=5, c=3

Thus it does not has real solutions.
Exactly 29.7, but you can't have 7/10 of a student so you round to 30. So 30 students are playing a music instrument because 330 times 0.09 is about 30
Answer: The cats cost more
also there is a typo
Step-by-step explanation:
I bought 1 dog and 3 cats a total cost of $7.75. the three cats cost more so in all the cats must cost 3.56$
You know you have two hours which will be the whole number. Then you take 36min and put it over 60min (total number of min in an hour) and you simplify by 6 to get 6/10 which can be simplified again to 3/5 so your final mixed number is
2 and 3/5 hours