Question

计算题：①(1-x^2)(1+x^2)-(1-2x^2)^2 ②(-2b^3分之a^2)^3除以4b^2分之3a^4

Answer 1

①(1-x^2)(1+x^2)-(1-2x^2)^2

=1-x^4-1+4x^2-4x^4

=4x^2-5x^4

②(-2b^3分之a^2)^3除以4b^2分之3a^4

=-2a^2/3b

③（2x/x-1）+（1/x+3)-(x^2+2x-3分之3x+5)

=[2x(x+3)+(x+1)-(3x+5)]/x^2+2x-3

=(2x^2+4x-6)/x^2+2x-3

=2