There are several ways to find the zeros of a quadratic function. One of my favorite is to use a graphing calculator to graph it. The zeros can be read directly from the graph.
The zeros are -5 and 6.
None of your options, not via complete the square nor quadratic the formula.
Solve for x over the real numbers:
x^2 + 8 x + 9 = 0
x = (-8 ± sqrt(8^2 - 4×9))/2 = (-8 ± sqrt(64 - 36))/2 = (-8 ± sqrt(28))/2:
x = (-8 + sqrt(28))/2 or x = (-8 - sqrt(28))/2
sqrt(28) = sqrt(4×7) = sqrt(2^2×7) = 2sqrt(7):
x = (2 sqrt(7) - 8)/2 or x = (-2 sqrt(7) - 8)/2
Factor 2 from -8 + 2 sqrt(7) giving 2 (sqrt(7) - 4):
x = 1/22 (sqrt(7) - 4) or x = (-2 sqrt(7) - 8)/2
(2 (sqrt(7) - 4))/2 = sqrt(7) - 4:
x = sqrt(7) - 4 or x = (-2 sqrt(7) - 8)/2
Factor 2 from -8 - 2 sqrt(7) giving 2 (-sqrt(7) - 4):
x = sqrt(7) - 4 or x = 1/22 (-sqrt(7) - 4)
(2 (-sqrt(7) - 4))/2 = -sqrt(7) - 4:
Answer: x = sqrt(7) - 4 or x = -sqrt(7) - 4_____________________________________________________
Solve for x:
x^2 + 8 x + 9 = 0
Subtract 9 from both sides:
x^2 + 8 x = -9
Add 16 to both sides:
x^2 + 8 x + 16 = 7
Write the left hand side as a square:
(x + 4)^2 = 7
Take the square root of both sides:
x + 4 = sqrt(7) or x + 4 = -sqrt(7)
Subtract 4 from both sides:
x = sqrt(7) - 4 or x + 4 = -sqrt(7)
Subtract 4 from both sides:
Answer: x = sqrt(7) - 4 or x = -4 - sqrt(7)
Answer:
B) 4.5
Step-by-step explanation:
The area of the first figure is 10x
The area of the second figure is 6(x+3)=6x+18
To solve, find the x that makes 10x=6x+18
1) 10x=6x+18
2) 4x=18
3) x=4.5
To check work)
1) 10(4.5)=6(4.5)+18
2) 45=27+18
3) 45=45
You would do 69sq×3.1416. that gives you 14,957.1576 round it to the nearest hundreth, 14,957.16
Answer:
Sampling is necessary because researchers in the social sciences almost never have enough resources — time or money — to collect information about the entire set of subjects of interest to them.
Step-by-step explanation:
Sampling is done because you usually cannot gather data from the entire population. Even in relatively small populations, the data may be needed urgently, and including everyone in the population in your data collection may take too long.
