(x-2) / (x ^ 2 + 6x + 9) - (x + 2) / (2x ^ 2-18)을 단순화하시오.

(x-2) / (x ^ 2 + 6x + 9) - (x + 2) / (2x ^ 2-18)을 단순화하시오.
Anonim

대답:

# (x ^ 2-15x + 6) / (2 (x-3) (x + 3) ^ 2) #

설명:

# x ^ 2 + 6x + 9 = (x + 3) (x + 3) = (x + 3) ^ 2 #

# 2x ^ 2-18 = 2 (x ^ 2-9) = 2 (x-3) (x + 3) #

2 칸의 차이 # (a-b) (a + b) = a ^ 2-b ^ 2 #

(x + 2) / (2 (x-3) (x + 3)) #

곱하기 by # 2 (x-3) (x + 3) ^ 2 #

= # ((x-3) (x-3) ^ 2) (x-3)

대괄호 확장

= # (2 (x ^ 2 + 5x + 6) - (x ^ 2 + 5x + 6)) / (2 (x-3) ^ 2) #

대괄호 확장

= # (2x ^ 2-10x + 12-x ^ 2-5x-6) / (2 (x-3) (x + 3) ^ 2) #

단순화

= # (x ^ 2-15x + 6) / (2 (x-3) (x + 3) ^ 2) #