Answer:
Negative numbers are anything below 0. They always have a minus (-) sign before them.
Positive numbers are anything above 0 and can sometimes be written with a plus (+) before them but not normally
Answer:
absolutely no idea if this is right but i put the first one
Step-by-step explanation:
Y = 18 x² + m x + 2
Exactly one x - intercept is for:
D = m² - 4 · 18 · 2 = 0
m² - 144 = 0
m² = 144
Answer:
m = -12 or m = 12
Answer:
Percentage of balls which are red = 80%.
Step-by-step explanation:
Let the probability of drawing a red ball be x then the probability of drawing a white ball is 1-x.
There are 5C3 = 10 ways of getting 3 reds in 5 draws so the probability of this is 10* x^3 * (1 - x)^2.
The probability of getting 1 red in 5 draws = 5C1 * x (1-x)^4.
The first probability is 32 times the last.
So we have the equation:
10x^3(1 - x)^2 / 5x(1 - x)^4 = 32
2x^2 / (1 - x)^2 = 32
2x^2 = 32(1 -x)^2
2x^2 = 32( 1 - 2x + x^2)
2x^2 = 32 - 64x + 32x^2
30x^2 - 64x + 32 = 0
15x^2 - 32x + 16 = 0
(5x - 4)(3x - 4) = 0
x = 0.8, 1.333...
The probability must be < 1 so x = 0.8 = 80%.
Let y be the number
y < 35