Answer:
65625/4(x^5)(y²)
Step-by-step explanation:
Using binomial expansion
Formula: (n k) (a^k)(b ^(n-k))
Where (n k) represents n combination of k (nCk)
From the question k = 5 (i.e. 5th term)
n = 7 (power of expression)
a = 5x
b = -y/2
....................
Solving nCk
n = 7
k = 5
nCk = 7C5
= 7!/(5!2!) ------ Expand Expression
=7 * 6 * 5! /(5! * 2*1)
= 7*6/2
= 21 ------
.........................
Solving (a^k) (b^(n-k))
a = 5x
b = -y/2
k = 5
n = 7
Substituting these values in the expression
(5x)^5 * (-y/2)^(7-5)
= (3125x^5) * (-y/2)²
= 3125x^5 * y²/4
= (3125x^5)(y²)/4
------------------------------------
Multiplying the two expression above
21 * (3125x^5)(y²)/4
= 65625/4(x^5)(y²)
Answer:
hi
Step-by-step explanation:
since power is positive in above expression
we get result as positive too
(-3)^6 = 729
(-3)^4= 81
________________
<h2>
729 × 81 × (-3)</h2>
______ (-177,147) ______
Answer:
0.8508
Step-by-step explanation:
In this question, we are asked to estimate the probability of getting at least 12 correct answers.
X ~ Bin ( n , p)
Where n = 60 , p = 1/4 = 0.25
Mean = np = 60 * 0.25 = 15
Standard deviation = sqrt [ n p ( 1 - p) ] = Sqrt [ 60 * 0.25 ( 1 - 0.25) ] = 3.3541
Using normal approximation
P(X < x) = P(Z < ( x - mean) / SD )
P(X >= 12) = P(X > 11.5)
= P(Z > ( 11.5 - 15) / 3.3541 )
= P(Z > -1.04)
= P(Z < 1.04)
= 0.8508