Answer:
The graph crosses the x-axis 2 times
The solutions are x = -8 & x = 4
Step-by-step explanation:
Qaudratics are in the form 
Where a, b, c are constants
Now, let's arrange this equation in this form:
Where
a = 1
b = 4
c = -32
We need to know the discriminant to know nature of roots. The discriminant is:
If
- D = 0 , we have 2 similar root and there is 2 solutions and that touches the x-axis
- D > 0, we have 2 distinct roots/solutions and both cut the x-axis
- D < 0, we have imaginary roots and it never cuts the x-axis
Let's find value of Discriminant:
Certainly D > 0, so there are 2 distinct roots and cuts the x-axis twice.
We get the roots/solutions by factoring:
Thus,
The graph crosses the x-axis 2 times
The solutions are x = -8 & x = 4
12. Answer: 2130
<u>Step-by-step explanation:</u>
T = -0.01y + 10.6
9.2 = -0.01y + 10.6
<u>-10.6</u> <u> -10.6 </u>
-1.4 = -0.01y
<u> ÷-0.01</u> <u>÷-0.01 </u>
140 = y
"y" represents the number of years after 1990
1990 + 140
= 2130
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13. Answer: -0.0036° per foot
<u>Step-by-step explanation:</u>
Since the relationship is linear, then we can set up the values as x, y coordinates and use the slope formula to find the rate of degrees over feet.
(6562, 63) and (16405, 28)
rate = 
= 
= 
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14. Answer: $0.28 per kWh
<u>Step-by-step explanation:</u>
Same reason as #13
(200, 55) and (500, 140)
rate = 
= 
= 
Answer:
There are multiple possibilities. One is there are 12 boys, and 16 girls. 12+16= 28 which is between 20 and 30. That would be 12:16, which can be simplified to 3:4. There is also 9 boys, and 12 girls. that would be 9:12, which can be simplified to 3:4. Also, 9 + 12 = 21, which is between 20 and 30.
