Question

[x(x的平方y的平方-xy)-y(x的平方-x的立方y)]/3x的平方y 其中x=根号2,y=-根号2

Answer 1

[x(x²y² - xy) - y(x² - x³y)] / 3x²y

= (x³y² - x²y - x²y + x³y²) / 3x²y

= (2x³y² - 2x²y) / 3x²y

= (2xy - 2)/3

= [ 2×√2×(-√2) - 2 ] /3

= (-4 - 2) / 3

= -2