Question

帮我看一下这个哪里错了。

1/2(t-4)(4t-16)+1/2[（4t-16)+(t-1)]×3-1/2(t-1)(t-1）
=1/2×（4t^2-16t-16t+64)+1/2×(4t^2-4t-16t+16)×3-1/2×(t^2-2t+1)
=2t^2-16t+32+1/2×（12t^2-60t+48)-1/2t^2+t-1/2
=2t^2-16t+32+6t^2-30t+24-1/2t^2+t-1/2
=15t^2-45t+111/2

Answer 1

1/2(t-4)(4t-16)+1/2[（4t-16)(t-1)]×3-1/2(t-1)(t-1）
=2(t-4)²+6(t-4)(t-1)-1/2(t-1)²
=2(t²-8t+16)+6(t²-5t+4)-1/2(t²-2t+1)
=2t²-16t+32+6t²-30t+24-t²/2+t-1/2
=15t²/2 -45t +111/2

你就最后一步错了。其它都对
2t²+6t²-1/2t²=15/2t²

追问

帮我算出结果。谢谢。

追答

1/2(t-4)(4t-16)+1/2[（4t-16)+(t-1)]×3-1/2(t-1)(t-1）
=1/2×（4t^2-16t-16t+64)+1/2×(4t^2-4t-16t+16)×3-1/2×(t^2-2t+1)
=2t^2-16t+32+1/2×（12t^2-60t+48)-1/2t^2+t-1/2
=2t^2-16t+32+6t^2-30t+24-1/2t^2+t-1/2
=15t^2/2-45t+111/2

请采纳，谢谢

追问

结果不对。谢谢

追答

那可能是你题目错了

追问

1/2(t-4)(4t-16)+1/2[（4t-16)+(t-1)]×3-1/2(t-1)(t-1）题目没错。

追答

你确定[（4t-16)+(t-1)] 是加，而不是乘吗？
你原来做的是乘

追问

就是加你用乘法分配律再做一遍

追答

1/2(t-4)(4t-16)+1/2[（4t-16)+(t-1)]×3-1/2(t-1)(t-1）
=2(t-4)²+6(t-4)+3(t-1)/2-1/2(t-1)²
=2(t²-8t+16)+6t-24-3t/2+3/2-1/2(t²-2t+1)
=2t²-16t+32+6t-24-3t/2+3/2-t²/2+t-1/2
=3t²/2 -21t/2 +9