Question

求几道数学题去括号,化简（3x^2-2x)+(4x-2x^2) 6a^2-4ab-a(2a^2+1/2ab)(3x^2-

Answer 1

1.（3x^2-2x)+(4x-2x^2) =3x^2-2x+4x-2x^2=x^2+2x

2.6a^2-4ab-a(2a^2+1/2ab) =6a^2-4ab-2a^3-1/2a^2b=-2a^3+(6-1/2b)a^2-4ab

3.(3x^2-2x+1)-(2x^2+3x-5) =3x^2-2x+1-2x^2-3x+5=x^2-5x+6

4.4-(2m+1)-2(3-5m) =4-2m-1-6+10m=8m-3

5.3a^2-(4b^2+5ab)+(2b^2-2a^2)=3a^2-4b^2-5ab+2b^2-2a^2

=a^2-5ab-2b^2=(1/10)^2-5(1/10)(1/5)-2(1/5)^2=-17/100=-0.17

6.B-A =(3xy-x^2)-(x^2+xy+y^2)=3xy-x^2-x^2-xy-y^2=-2x^2+2xy-y^2

7.5+b-a-(b-a)^2=5-(a-b)-(a-b)^2=5-4-4^2=-15