【计算】(2m-5)(2m+5)-(2m+1)(2m-3)-2(m-1)^2
问题描述:
【计算】(2m-5)(2m+5)-(2m+1)(2m-3)-2(m-1)^2
答
(2m-5)(2m+5)-(2m+1)(2m-3) - 2(m-1)^2
=4m²-25-(4m²-4m-3) - (2m²-4m+2)
=4m²-25-4m²+4m+3 -2m²+4m-2
=-24+8m -2m²
=-2(m²-4m+12)
答
(2m-5)(2m+5)-(2m+1)(2m-3)-2(m-1)^2
=4m²-25-(4m²-6m+2m-3)-2(m²-2m+1)
=4m²-25-4m²+4m+3-2m²+4m-2
=-2m²+8m-24