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:
Slope: 1/2
Explanation: Slope=rise/run
Y-Intercept: 4
Explanation: Y-intercept is the Y value where X=0
Answer:
- geometric sequence with initial value 20 and common ratio 1/2
- average rate of change on [1, 3] = -7.5
Step-by-step explanation:
(a) The given points have sequential values of x and values of y that are each 1/2 the value before. The common ratio tells us the sequence is a geometric sequence.
(b) The first given point is (2, 10), so extrapolating backward, we determine the previous point to be ...
... (2-1, 10/(1/2)) = (1, 20)
Thus, we have enough information to determine the average slope between n=1 and n=3.
... (difference in y)/(difference in n) = (5 -20)/(3 -1) = -15/2 = -7.5
answers B and D are clearly wrong and if u do some simple thinking you can determine the answer is C...
Have a fantabulous day! :)
Certain or very likely its one of those two i hope i helped
