a) A=a(a-b)-b(a-b)=(a-b)(a-b)=(a-b)2
a)\(A=a\left(a-b\right)-b\left(a-b\right)\)
\(=a^2-ab-ab+b^2\)
\(=a^2-2b+b^2\\ =\left(a-b\right)^2\)
b)\(B=m\left(-2m^2+1\right)+m^2\left(2m^2+1\right)-m\)
\(=-2m^4+m+2m^4+m^3-m\)
\(=m^2\)
c)\(C=\left(-2t\right)^2\left(t+2\right)-8t^2\left(1-t\right)-4t^3\)
\(=4t^2.\left(t+2\right)-8t^2\left(1-t\right)-4t^3\)
\(=4t^3+8t^2-8t^2+8t^3-4t^3\\ =8t^3\)
a) Ta có: \(A=a\left(a-b\right)-b\left(a-b\right)\)
\(=\left(a-b\right)^2\)
\(=a^2-2ab+b^2\)
b) Ta có: \(B=m\left(-2m^3+1\right)+m^2\left(2m^2+1\right)-m\)
\(=-2m^4+m+2m^4+m^2-m\)
\(=m^2\)
