(3x+1)+(-x-2)(-3x+9)+(-8+5x)(5x+9)-(-7x+7)어떻게 계산 합 니까?

(3x+1)+(-x-2)(-3x+9)+(-8+5x)(5x+9)-(-7x+7)어떻게 계산 합 니까?

1、 (3x+1)+(-x-2)
=3X+1-X-2
=2X-1
2、(-3x+9)+(-8+5x)
=-3X+9-8+5X
=2X+1
3、(5x+9)-(-7x+7)
=2X+9+7X-7
=9X+16.