Soalan # 832b7

Soalan # 832b7
Anonim

Jawapan:

# = 360 * a ^ 7 * b * c ^ 2 + 840 * a ^ 6 * b ^ 3 * c + 252 * a ^ 5 * b ^ 5 #

Penjelasan:

# "Nama" #

#p (x) = b * x + c * x ^ 2 = x (b + c * x) #

# "Kemudian kita ada" #

(x)) ^ 10 = sum_ {i = 0} ^ {i = 10} C (10, i) * a ^ (10-i) * p (x)

# = sum_ {i = 0} ^ {i = 10} C (10, i) * a ^ (10-i) * x ^ i * (b + c * x)

# "dengan" C (n, k) = (n!) / ((n-k)! k!) "(kombinasi)" #

# = sum_ {i = 0} ^ {i = 10} C (10, i) * a ^ (10-i) * x ^ i * sum_ {j = 0} j) * b ^ (ij) * (c * x) ^ j #

# "pekali" x ^ 5 "bermaksud" i + j = 5 => j = 5-i "."

# => C5 = sum_ {i = 0} ^ {i = 5} C (10, i) * C (i, 5-i) * a ^ (10-i) * c ^ (5-i) #

# => C5 = C (10,3) * C (3,2) * a ^ 7 * b * c ^ 2 + C (10,4) * C (4,1) * a ^ 6 * b ^ * c + C (10,5) * C (5,0) * a ^ 5 * b ^ 5 #

# = 360 * a ^ 7 * b * c ^ 2 + 840 * a ^ 6 * b ^ 3 * c + 252 * a ^ 5 * b ^ 5 #