全部是解方程,用初中的算式来解1:3-2(x+5)=-x+1 2:5(x-2)=4-(14-x) 3:1/3(x+1)-
1个回答

3-2(x+5)=-x+1

3-2x-10=-x+1

x=-8

5(x-2)=4-(14-x)

5x-10=4-14+x

4x=0

x=0

1/3(x+1)-x=1/7(2x-3)

7x+7-21x=6x-9

20x=16

x=0.8

1/5x-3-2x/2=1

2x-30-10x=10

8x=-40

x=-5

4-(-1)3次方/0.5*2

=4-(-1)*2*2

=4+4=8

(3x的2次方-xy-2y的2次方)-2(x的2次方+xy-2y的2次方)

=3x^2-xy-2y^2-2x^2-2xy+4y^2

=x^2-3xy+2y^2

=(x-2y)(x-y)

3x的2次方+(2x的2次方-3x)-(5x的2次方-x)

=3x^2+2x^2-3x-5x^2-x

=-4x=-4*(-1)=4