The graph below shows three different normal distributions. 3 normal distributions are shown. All 3 are at different points on the axis. They all have different heights and widths. Which statement must be true? Each distribution has the same mean and the same standard deviation. Each distribution has the same mean and a different standard deviation. Each distribution has a different mean and the same standard deviation. Each distribution has a different mean and a different standard deviation.

his chances of getting a coin of higher value is 4/19

step-by-step explanation:

x^2 + 81

we can factor this using difference of square binomials.

rewrite the equation:

x^2 - (-81)

factor:

(a^2 - b^2) = (√a^2 + √b^2)(√a^2 - √b^2)

(x^2 - (-81) = (x + √-81)(x - √-81)

we can remove the - from under the radical by multiplying it by i.

(x^2 - (-81) = (x + i√81)(x - i√81)

(x^2 - (-81) = (x + 9i)(x - 9i)

we can check our answer by using foil:

x^2 - 9ix + 9ix - 81i^2

x^2 - 81^2

i^2 = -1

x^2 + 81

the answer is b to that quesiton