Answer:
a = 3
Step-by-step explanation:
1) Simplify 5a - 9 + a to 6a - 9.
2) Add 9 to both sides.
3) Simplify 9 + 9 to 18.
4) Divide both sides by 6.
5) Simplify 18/6 to 3.
Therefor, the answer is, a = 3.
Answer:
The slope of the line will change from negative to positive
Step-by-step explanation:
the equation is in the form of y=mx+c and m is negative. By multiplying m with another negative number it turns positive, thus slope changes from negative to positive
I assume that the parabola in this particular problem is one whose axis of symmetry is parallel to the y axis. The formula we're going to use in this case is (x-h)2=4p(y-k). We know variables h and k from the vertex (1,20) but p is not given. However, we can solve for p by substituting values x and y in the formula with the y-intercept:
(0-1)^2=4p(16-20)
Solving for p, p=-1/16.
Going back to the formula, we can finally solve for the x-intercepts. Simply fill in variables p, h and k then set y to zero:
(x-1)^2=4(-1/16)(0-20)
(x-1)^2=5
x-1=(+-)sqrt(5)
x=(+-)sqrt(5)+1
Here, we have two values of x
x=sqrt(5)+1 and
x=-sqrt(5)+1
thus, the answers are: (sqrt(5)+1,0) and (-sqrt(5)+1,0).
The normal rule to remember is 68-95-99.7, i.e. plus or minus three sigma corresponds to 99.7% of the probability. That leaves 0.3% in the two tails, or 0.15% in the tail above 3 sigma.
Answer: 0.15%
