Question

(x+y²)+(2x+1/1×2·y²）+(3x+1/2×3·y²)+……+(9x+1/8×9·y²)

Answer 1

你好！
解：（X+Y²;)+(2X+1/1*2 *Y²;)+...+(9X+1/8*9 *Y²;)
=（X+y^2）+（2X+1/2Y^2）+（3X+1/2*1/3Y^2）+...+（9X+1/8*1/9Y^2）

=X+y^2+2X+1/2y^2+3X+1/6Y^2+...+9X+1/72Y^2

=45X+1/2Y^2+1/6Y^2+1/12Y^2+1/20Y^2+1/30Y^2+1/42Y^2+1/56Y^2+1/72Y^2

=45X+1/2Y^2+...+1/72Y^2

=45X+(1/2+1/6+...+1/72)Y^2

=45X+[(1—1/2)+(1/2—1/3)+...+(1/8-1/9)]Y^2

=45X+(1-1/9)]Y^2

=45X+8/9Y^2
【若是化简求值，将X,Y代入即可】
祝楼主钱途无限，事事都给力！