The probability of rolling an even number on a six sided die is 1/3.
The standard eqn of a parabola in vertex form is y-k = a(x-h)^2, where (h,k) is the vertex. There are a good number of steps involved. I don't think it wise not to "show work." I cannot answer this question without going through all those steps.
However, there's an easier way to find the vertex. Identify the coefficients a, b and c:
a= -4, b= -3 and c = 1
Then the x-coord. of the vertex is x = -b / (2a). Subst. -3 for b and -4 for a and simplify. x = ??
Then find the y-coord. of the vertex by subbing your result, above, into the original equation.
Write the vertex as (h,k).
Once you have this vertex, you can find the equation in vertex form as follows:
Start with the general form y-k = a(x-h)^2, where (h,k) is the vertex.
You've already found the vertex (h,k). Subst. h and k into the general form, above. Then only the coefficient "a" remains undefined.
The objective is to get the variable (x) alone. To do this start be subtracting 3. What you do to one side you have to do to the other so you have to subtract three from the other side of the equal sign as well. So now you have:
20x= 17-3 subtract the 3 to get 20x=14
Now because the 20 is attached to the x In order to get the x alone you have to divide by 20:
20x/20. =14/20 divide 14 by 20
X=.7 or x=7/10
X < 7! just add 4 to both sides.