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.
Answer: x = $7, y = $6
Step-by-step explanation:
Let x be the cost of an adult ticket
Let y be the cost of a children's ticket
Translate these sentences to algebra:
At the circus, three adult tickets and five child tickets cost $51: 3x + 5y = 51
Five adult tickets and two child tickets cost $47: 5x + 2y = 47
Now we have two equations. Let's use substitution to solve.
3x + 5y = 51
3x = 51 - 5y
.: x = 17 - 5y/3
Now substitute this value of x into the second equation to find the numerical value of y:
5(17 - 5y/3) + 2y = 47
85 - 25y/3 + 2y = 47
-19y/3 = -38
-19y = -114
.: y = 6
Now find x:
x = 17 - 5y/3
x = 17 - 10
.: x = 7
So an adult ticket costs $7, and a child ticket costs $6 :)
We can set up a proportion.
32/128 = x/100
32 * 100 = 3200
128 * x = 128x.
Now we have 128x = 3200.
All we need to do is divide 3200 by 128, so 3200 / 128 = 25, so your answer is 25%.
Answer:
x = 18.5
Step-by-step explanation:
Multiply 5 and 3.7.
Which equals 18.5.
Check: 18.5 / 3.7 = 5.√