Question

（-2）^3×(-1)^4-|-12|÷[-(-1/2)^2]

Answer 1

（-2）^3×(-1)^4-|-12|÷[-(-1/2)^2]=-8x1-12x(-4)=-8+48=40;

12xy+(3x^2-5xy)-2(3xy+2x^2)=12xy+3x^2-5xy-6xy-4x^2=xy-x^2;

3x^2+[x^2+(5x^2-2x)-2(x^2-3x)]=3x^2+[x^2+5x^2-2x-2x^2+6x]=

3x^2+[4x^2+4x]=7x^2+4x=7x2^2+4x2=7x4+8=28+8=36