Question

(2x^1/2+3y-7/4)(2x^1/2-3y-1/4)怎么算

Answer 1

[ 2x^(1/2) +3y^(-7/4)]*[2x^(1/2) -3y^(-1/4)]

= 2x^(1/2)·2x^(1/2) - 2x^(1/2)·3y^(-1/4) +3y^(-7/4)·2x^(1/2) -3y^(-7/4)·3y^(-1/4)

=4x - 6x^(1/2)·y^(-1/4) + 6y^(-7/4)·x^(1/2) -9y^(-2)

=4x - 6x^(1/2)·y^(-1/4)·[1+ y^(-3/2)] - 9y^(-2)