初一数学题。。会的哥哥姐姐们请进
解答:
1。(1)(4x²y-3xy²)-(-5x²y+2xy²)
=4x²y-3xy²+5x²y-2xy²
=9x²y-5xy²
(2)-2[(1/3)x-2y+z]+3(x-z)
=-(2/3)x+4y-2z+3x-3z
=(7/3)x+4y-5z
(3)(-b)³·(-b²)
=-b³·(-b²)
=b^5【注:b^5表示b的5次方】
(4)a²·a³+a·a^4
=a^5+a^5
=2a^5
(5)b^(2n-1)·b+b^...全部
解答:
1。(1)(4x²y-3xy²)-(-5x²y+2xy²)
=4x²y-3xy²+5x²y-2xy²
=9x²y-5xy²
(2)-2[(1/3)x-2y+z]+3(x-z)
=-(2/3)x+4y-2z+3x-3z
=(7/3)x+4y-5z
(3)(-b)³·(-b²)
=-b³·(-b²)
=b^5【注:b^5表示b的5次方】
(4)a²·a³+a·a^4
=a^5+a^5
=2a^5
(5)b^(2n-1)·b+b^n·b^n
=b^(2n)+b^(2n)
=2b^(2n)
(6)(a-b)^4·(a-b)·(a-b)²=(a-b)^7
(7)-a³·(-a²)·(-a)^4
=a³·a²·a^4
=a^9
(8)(m-n)³·(n-m)^4
=(m-n)³·(m-n)^4
=(m-n)^7
(9)2(a²)^6-(a³)^4
=2a^12-a^12
=a^12
(10)[(x²)³·x³]³
=[x^6·x³]³
=[x^9]³
=x^27
2。
(1)根据三角形两边之和大于第三边得:
7-2
。收起