Answer:
No of white balls = 5
Step-by-step explanation:
Given that,
Total no of red balls = 4
Total no of green balls = 6
The probability of not drawing a white ball in one draw be,
We need to find the number of white balls. Let there are x balls.
The probability of drawing a white ball = 1 - the probability of not drawing a white ball
= 1 -2/3
= 1/3
Using the formula for solving probability of having a white ball.
Hence, there are 5 white balls.
Answer:
x ≈ - 5.32, x ≈ 1.32
Step-by-step explanation:
Given
x² + 4x - 7 = 0 ( add 7 to both sides )
x² + 4x = 7
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(2)x + 4 = 7 + 4
(x + 2)² = 11 ( take the square root of both sides )
x + 2 = ± ( subtract 2 from both sides )
x = - 2 ±
Thus
x = - 2 - ≈ - 5.32 ( to 2 dec. places )
x = - 2 + ≈ 1.32 ( to 2 dec. places )
if we zero out f(x), namely make y = 0, we can get the roots or x-intercepts for this quadratic equation
now, the equation is in x-terms, meaning is a vertically opening parabola, so the axis of symmetry will be x = something, a vertical line.
well, we have two x-intercepts, one at -4 and another at 2, and the vertex is right half-way between those guys
-4------------(-1)------------2
so the vertex is at x=-1, namely the axis of symmetry is x = -1.