Question

Y分之2X等于2y平方分之4xy

Answer 1

① Y分之2X等于2y平方分之4xy

y/2x=2*2y/2x*2y=2y^2/4xy(分子分母同乘以2y)

② 9a平方b分之6ac等于3ab分之2c

6ac/9a^2b=（6ac÷3a）/(9a^2b÷3a)=2c/3ab(分子分母同除以3a)

③x+y分之x-y等于（x+y）平方分之x平方-y平方

（x-y）/(x+y)=(x-y)(x+y)/(x+y)^2=(x^2-y^2)/(x+y)^2(分子分母同乘以x+y)